| Words | Parts of Speech | Meaning/Definition/Similar Words |
|---|---|---|
| oathbreaking | noun | The violation of an oath; perjury. |
| obcompressed | adjective | Compressed or flattened antero-posteriorly, or in a way opposite to the usual one. |
| obedienciary | noun | One yielding obedience. |
| oblanceolate | adjective | Lanceolate in the reversed order, that is, narrowing toward the point of attachment more than toward the apex. |
| obligatorily | adverb | In an obligatory manner; by reason of obligation. |
| obliterating | present participle & vb. noun | of Obliterate |
| obliteration | noun | The act of obliterating, or the state of being obliterated; extinction. |
| obliterative | adjective | Tending or serving to obliterate. |
| oblong-ovate | adjective | Between oblong and ovate, but inclined to the latter. |
| obmutescence | noun | A becoming dumb; loss of speech., A keeping silent or mute. |
| obreptitious | adjective | Done or obtained by surprise; with secrecy, or by concealment of the truth. |
| obscurantism | noun | The system or the principles of the obscurants. |
| obscurantist | noun | Same as Obscurant. |
| obsequiously | adverb | In an obsequious manner; compliantly; fawningly., In a manner appropriate to obsequies. |
| observantine | noun | One of a branch of the Order of Franciscans, who profess to adhere more strictly than the Conventuals to the intention of the founder, especially as to poverty; — called also Observants. |
| observership | noun | The office or work of an observer. |
| obsolescence | noun | The state of becoming obsolete. |
| obsoleteness | noun | The state of being obsolete, or no longer used; a state of desuetude., Indistinctness; want of development. |
| obstetricate | verb i. | To perform the office of midwife., To assist as a midwife. |
| obstetrician | noun | One skilled in obstetrics; an accoucheur. |
| obstreperous | adjective | Attended by, or making, a loud and tumultuous noise; clamorous; noisy; vociferous. |
| obtrectation | noun | Slander; detraction; calumny. |
| obtruncation | noun | The act of lopping or cutting off. |
| obtrusionist | noun | One who practices or excuses obtrusion. |
| obtusangular | adjective | See Obstuseangular. |
| occasionable | adjective | Capable of being occasioned or caused. |
| occasionally | adverb | In an occasional manner; on occasion; at times, as convenience requires or opportunity offers; not regularly. |
| oceanography | noun | A description of the ocean. |
| ochroleucous | adjective | Yellowish white; having a faint tint of dingy yellow. |
| octogenarian | noun | A person eighty years, or more, of age. |
| octopetalous | adjective | Having eight petals or flower leaves. |
| octoradiated | adjective | Having eight rays. |
| octospermous | adjective | Containing eight seeds. |
| octostichous | adjective | In eight vertical ranks, as leaves on a stem. |
| octosyllabic | adjective | Alt. of Octosyllabical |
| octosyllable | adjective | Octosyllabic., A word of eight syllables. |
| odontography | noun | A description of the teeth. |
| odontopteryx | noun | An extinct Eocene bird having the jaws strongly serrated, or dentated, but destitute of true teeth. It was found near London. |
| odontotormae | nounpl. | An order of extinct toothed birds having the teeth in sockets, as in the genus Ichthyornis. See Ichthyornis. |
| oenanthylate | noun | A salt of /nanthylic acid; as, potassium oenanthylate. |
| oenanthylous | adjective | Of, pertaining to, or designating, an acid formerly supposed to be the acid of oenanthylic ether, but now known to be a mixture of higher acids, especially capric acid. |
| officeholder | noun | An officer, particularly one in the civil service; a placeman. |
| old-womanish | adjective | Like an old woman; anile. |
| oligarchical | adjective | Of or pertaining to oligarchy, or government by a few. |
| olla-podrida | noun | A favorite Spanish dish, consisting of a mixture of several kinds of meat chopped fine, and stewed with vegetables., Any incongruous mixture or miscellaneous collection; an olio. |
| omander wood | The wood of Diospyros ebenaster, a kind of ebony found in Ceylon. | |
| omnipotently | adverb | In an omnipotent manner. |
| omnipresence | noun | Presence in every place at the same time; unbounded or universal presence; ubiquity. |
| omnipresency | noun | Omnipresence. |
| omnispective | adjective | Beholding everything; capable of seeing all things; all-seeing. |
| omphalomancy | noun | Divination by means of a child’s navel, to learn how many children the mother may have. |
| onagrarieous | adjective | Pertaining to, or resembling, a natural order of plants (Onagraceae or Onagrarieae), which includes the fuchsia, the willow-herb (Epilobium), and the evening primrose (/nothera). |
| oneirocritic | adjective | An interpreter of dreams., Alt. of Oneirocritical |
| onomatopoeia | noun | The formation of words in imitation of sounds; a figure of speech in which the sound of a word is imitative of the sound of the thing which the word represents; as, the buzz of bees; the hiss of a goose; the crackle of fire. |
| onomatopoeic | adjective | Onomatopoetic. |
| oophorectomy | noun | Ovariotomy. |
| oophoridiums | plural | of Oophoridium |
| oosporangium | noun | An oogonium; also, a case containing oval or rounded spores of some other kind than oospores. |
| open-hearted | adjective | Candid; frank; generous. |
| open-mouthed | adjective | Having the mouth open; gaping; hence, greedy; clamorous. |
| operculiform | adjective | Having the form of a lid or cover. |
| ophiological | adjective | Of or pertaining to ophiology. |
| ophiophagous | adjective | Feeding on serpents; — said of certain birds and reptiles. |
| ophiurioidea | noun pl. | Alt. of Ophiuroidea |
| opiniastrous | adjective | See Opiniaster. [Obs.]. |
| opinionately | adverb | Conceitedly. |
| opinionatist | noun | An opinionist. |
| opinionative | adjective | Unduly attached to one’s own opinions; opinionated., Of the nature of an opinion; conjectured. |
| opisthotonos | noun | A tetanic spasm in which the body is bent backwards and stiffened. |
| opposability | noun | The condition or quality of being opposable. |
| oppositeness | noun | The quality or state of being opposite. |
| orang-outang | noun | An arboreal anthropoid ape (Simia satyrus), which inhabits Borneo and Sumatra. Often called simply orang. |
| orbiculation | noun | The state or quality of being orbiculate; orbicularness. |
| orchidaceous | adjective | Pertaining to, or resembling, a natural order (Orchidaceae) of endogenous plants of which the genus Orchis is the type. They are mostly perennial herbs having the stamens and pistils united in a single column, and normally three petals and three sepals, all adherent to the ovary. The flowers are curiously shaped, often resembling insects, the odd or lower petal (called the lip) being unlike the others, and sometimes of a strange and unexpected appearance. About one hundred species occur in the United States, but several thousand in the tropics. |
| ordinability | noun | Capability of being ordained or appointed. |
| ordinaryship | noun | The state of being an ordinary. |
| oregon grape | An evergreen species of barberry (Berberis Aquifolium), of Oregon and California; also, its roundish, blue-black berries. | |
| organization | noun | The act of organizing; the act of arranging in a systematic way for use or action; as, the organization of an army, or of a deliberative body., The state of being organized; also, the relations included in such a state or condition., That which is organized; an organized existence; an organism, an arrangement of parts for the performance of the functions necessary to life. |
| organography | noun | A description of the organs of animals or plants. |
| organoleptic | adjective | Making an impression upon an organ; plastic; — said of the effect or impression produced by any substance on the organs of touch, taste, or smell, and also on the organism as a whole. |
| orichalceous | adjective | Pertaining to, or resembling, orichalch; having a color or luster like that of brass. |
| orientalized | imp. & past participle | of Orientalize |
| originalness | noun | The quality of being original; originality. |
| ornamentally | adverb | By way of ornament. |
| ornithologic | adjective | Alt. of Ornithological |
| ornithomancy | noun | Divination by means of birds, their flight, etc. |
| ornithopappi | noun pl. | An extinct order of birds. It includes only the Archaeopteryx. |
| ornithoscopy | noun | Observation of birds and their habits. |
| orographical | adjective | Of or pertaining to orography. |
| orthoclastic | adjective | Breaking in directions at right angles to each other; — said of the monoclinic feldspars. |
| orthodoxally | adverb | Orthodoxly. |
| orthodoxical | adjective | Pertaining to, or evincing, orthodoxy; orthodox. |
| orthodoxness | noun | The quality or state of being orthodox; orthodoxy. |
| orthodromics | noun | The art of sailing in a direct course, or on the arc of a great circle, which is the shortest distance between any two points on the surface of the globe; great-circle sailing; orthodromy. |
| orthognathic | adjective | Orthognathous. |
| orthogonally | adverb | Perpendicularly; at right angles; as, a curve cuts a set of curves orthogonally. |
| orthographer | noun | One versed in orthography; one who spells words correctly. |
| orthographic | adjective | Alt. of Orthographical |
| orthomorphic | adjective | Having the right form. |
| orthopedical | adjective | Pertaining to, or employed in, orthopedy; relating to the prevention or cure of deformities of children, or, in general, of the human body at any age; as, orthopedic surgery; an orthopedic hospital. |
| orthopterous | adjective | Of or pertaining to the Orthoptera. |
| orthorhombic | adjective | Noting the system of crystallization which has three unequal axes at right angles to each other; trimetric. See Crystallization. |
| orthosilicic | adjective | Designating the form of silicic acid having the normal or highest number of hydroxyl groups. |
| orthotropous | adjective | Having the axis of an ovule or seed straight from the hilum and chalaza to the orifice or the micropyle; atropous. |
| oryctography | noun | Description of fossils. |
| oryctologist | noun | One versed in oryctology. |
| osage orange | An ornamental tree of the genus Maclura (M. aurantiaca), closely allied to the mulberry (Morus); also, its fruit. The tree was first found in the country of the Osage Indians, and bears a hard and inedible fruit of an orangelike appearance. See Bois d’arc. | |
| oscillatoria | noun pl. | Same as Oscillaria. |
| osculatrixes | plural | of Osculatrix |
| ossification | noun | The formation of bone; the process, in the growth of an animal, by which inorganic material (mainly lime salts) is deposited in cartilage or membrane, forming bony tissue; ostosis., The state of being changed into a bony substance; also, a mass or point of ossified tissue. |
| ostentatious | adjective | Fond of, or evincing, ostentation; unduly conspicuous; pretentious; boastful. |
| osteocommata | plural | of Osteocomma |
| osteocranium | noun | The bony cranium, as distinguished from the cartilaginous cranium. |
| osteodentine | noun | A hard substance, somewhat like bone, which is sometimes deposited within the pulp cavity of teeth. |
| osteogenesis | noun | Alt. of Osteogeny |
| osteogenetic | adjective | Connected with osteogenesis, or the formation of bone; producing bone; as, osteogenetic tissue; the osteogenetic layer of the periosteum. |
| osteographer | noun | An osteologist. |
| osteological | adjective | Of or pertaining to osteology. |
| osteomalacia | noun | A disease of the bones, in which they lose their earthy material, and become soft, flexible, and distorted. Also called malacia. |
| osteoplastic | adjective | Producing bone; as, osteoplastic cells., Of or pertaining to the replacement of bone; as, an osteoplastic operation. |
| osteosarcoma | noun | A tumor having the structure of a sacroma in which there is a deposit of bone; sarcoma connected with bone. |
| ostracodermi | noun pl. | A suborder of fishes of which Ostracion is the type. |
| otacousticon | noun | An instrument to facilitate hearing, as an ear trumpet. |
| ouranography | noun | See Uranography. |
| outgeneraled | imp. & past participle | of Outgeneral |
| outmanoeuvre | verb t. | To surpass, or get an advantage of, in maneuvering; to outgeneral. |
| outstripping | present participle & vb. noun | of Outstrip |
| ovariotomist | noun | One who performs, or is skilled in, ovariotomy. |
| ovate-oblong | adjective | Oblong. with one end narrower than the other; ovato-oblong. |
| ovato-oblong | adjective | Same as Ovate-oblong. |
| overcautious | adjective | Too cautious; cautious or prudent to excess. |
| overdelicate | adjective | Too delicate. |
| overestimate | verb t. | To estimate too highly; to overvalue., An estimate that is too high; as, an overestimate of the vote. |
| overexertion | noun | Excessive exertion. |
| overflourish | verb t. | To make excessive display or flourish of., To embellish with outward ornaments or flourishes; to varnish over. |
| overfrequent | adjective | Too frequent. |
| overfruitful | adjective | Too fruitful. |
| overfullness | noun | The state of being excessively or abnormally full, so as to cause overflow, distention, or congestion; excess of fullness; surfeit. |
| over-garment | noun | An outer garment. |
| overgarrison | verb t. | To garrison to excess. |
| overlaboring | present participle & vb. noun | of Overlabor |
| overlordship | noun | Lordship or supremacy of a person or a people over others. |
| overluscious | adjective | Excessively luscious. |
| overmalapert | adjective | Excessively malapert or impudent. |
| overmeddling | noun | Excessive interference. |
| overmoisture | noun | Excess of moisture. |
| overmuchness | noun | The quality or state of being in excess; superabundance. |
| overmultiply | verb t. & i. | To multiply or increase too much; to repeat too often. |
| overnumerous | adjective | Excessively numerous; too many. |
| overpersuade | verb t. | To persuade or influence against one’s inclination or judgment. |
| overpowering | present participle & vb. noun | of Overpower, Excelling in power; too powerful; irresistible. |
| overpraising | noun | The act of praising unduly; excessive praise. |
| overpressure | noun | Excessive pressure or urging. |
| overreaching | present participle & vb. noun | of Overreach |
| overrigorous | adjective | Too rigorous; harsh. |
| oversaturate | verb t. | To saturate to excess. |
| overseership | noun | The office of an overseer. |
| overshadowed | imp. & past participle | of Overshadow |
| overshadower | noun | One that throws a shade, or shadow, over anything. |
| overshooting | present participle & vb. noun | of Overshoot |
| overstepping | present participle & vb. noun | of Overstep |
| overstocking | present participle & vb. noun | of Overstock |
| overstrained | imp. & past participle | of Overstrain |
| overstraitly | adverb | Too straitly or strictly. |
| overstudious | adjective | Too studious. |
| overthrowing | present participle & vb. noun | of Overthrow |
| overthwartly | adverb | In an overthwart manner; across; also, perversely. |
| overtroubled | adjective | Excessively troubled. |
| overturnable | adjective | Capable of being, or liable to be, overturned or subverted. |
| overwhelming | present participle & vb. noun | of Overwhelm, Overpowering; irresistible. |
| oxalethyline | noun | A poisonous nitrogenous base (C6H10N2) obtained indirectly from oxamide as a thick transparent oil which has a strong narcotic odor, and a physiological action resembling that of atropine. It is probably related to pyridine. |
| oxamethylane | noun | Methyl oxamate, obtained as a pearly white crystalline substance. |
| oxanillamide | noun | A white crystalline nitrogenous substance, obtained indirectly by the action of cyanogen on aniline, and regarded as an anilide of oxamic acid; — called also phenyl oxamide. |
| oxygenizable | adjective | Oxidizable. |
| oxymethylene | noun | Formic aldehyde, regarded as a methylene derivative. |
| oxyquinoline | noun | Hydroxy quinoline; a phenol derivative of quinoline, — called also carbostyril. |
| oxysulphuret | noun | An oxysulphide. |
| oyster-green | noun | A green membranous seaweed (Ulva) often found growing on oysters but common on stones, piles, etc. |