| Words | Parts of Speech | Meaning/Definition/Similar Words |
|---|---|---|
| oncidium | noun | A genus of tropical orchidaceous plants, the flower of one species of which (O. Papilio) resembles a butterfly. |
| oncotomy | noun | The opening of an abscess, or the removal of a tumor, with a cutting instrument. |
| oneberry | noun | The herb Paris. See Herb Paris, under Herb. |
| one-hand | adjective | Employing one hand; as, the one-hand alphabet. See Dactylology. |
| onerated | imp. & past participle | of Onerate |
| onliness | noun | The state of being alone. |
| onocerin | noun | A white crystalline waxy substance extracted from the root of the leguminous plant Ononis spinosa. |
| onomancy | noun | Divination by the letters of a name; nomancy. |
| ontogeny | noun | The history of the individual development of an organism; the history of the evolution of the germ; the development of an individual organism, — in distinction from phylogeny, or evolution of the tribe. Called also henogenesis, henogeny. |
| ontology | noun | That department of the science of metaphysics which investigates and explains the nature and essential properties and relations of all beings, as such, or the principles and causes of being. |