4 letter word starting with op

Words Parts of Speech Meaning/Definition/Similar Words
opah noun A large oceanic fish (Lampris quttatus), inhabiting the Atlantic Ocean. It is remarkable for its brilliant colors, which are red, green, and blue, with tints of purple and gold, covered with round silvery spots. Called also king of the herrings.
opal noun A mineral consisting, like quartz, of silica, but inferior to quartz in hardness and specific gravity.
open adjective Free of access; not shut up; not closed; affording unobstructed ingress or egress; not impeding or preventing passage; not locked up or covered over; — applied to passageways; as, an open door, window, road, etc.; also, to inclosed structures or objects; as, open houses, boxes, baskets, bottles, etc.; also, to means of communication or approach by water or land; as, an open harbor or roadstead., Free to be used, enjoyed, visited, or the like; not private; public; unrestricted in use; as, an open library, museum, court, or other assembly; liable to the approach, trespass, or attack of any one; unprotected; exposed., Free or cleared of obstruction to progress or to view; accessible; as, an open tract; the open sea., Not drawn together, closed, or contracted; extended; expanded; as, an open hand; open arms; an open flower; an open prospect., Without reserve or false pretense; sincere; characterized by sincerity; unfeigned; frank; also, generous; liberal; bounteous; — applied to personal appearance, or character, and to the expression of thought and feeling, etc., Not concealed or secret; not hidden or disguised; exposed to view or to knowledge; revealed; apparent; as, open schemes or plans; open shame or guilt., Not of a quality to prevent communication, as by closing water ways, blocking roads, etc.; hence, not frosty or inclement; mild; — used of the weather or the climate; as, an open season; an open winter., Not settled or adjusted; not decided or determined; not closed or withdrawn from consideration; as, an open account; an open question; to keep an offer or opportunity open., Free; disengaged; unappropriated; as, to keep a day open for any purpose; to be open for an engagement., Uttered with a relatively wide opening of the articulating organs; — said of vowels; as, the an far is open as compared with the a in say., Uttered, as a consonant, with the oral passage simply narrowed without closure, as in uttering s., Not closed or stopped with the finger; — said of the string of an instrument, as of a violin, when it is allowed to vibrate throughout its whole length., Produced by an open string; as, an open tone., Open or unobstructed space; clear land, without trees or obstructions; open ocean; open water., To make or set open; to render free of access; to unclose; to unbar; to unlock; to remove any fastening or covering from; as, to open a door; to open a box; to open a room; to open a letter., To spread; to expand; as, to open the hand., To disclose; to reveal; to interpret; to explain., To make known; to discover; also, to render available or accessible for settlements, trade, etc., To enter upon; to begin; as, to open a discussion; to open fire upon an enemy; to open trade, or correspondence; to open a case in court, or a meeting., To loosen or make less compact; as, to open matted cotton by separating the fibers., To unclose; to form a hole, breach, or gap; to be unclosed; to be parted., To expand; to spread out; to be disclosed; as, the harbor opened to our view., To begin; to commence; as, the stock opened at par; the battery opened upon the enemy., To bark on scent or view of the game.
opie noun Opium.
opus noun A work; specif. (Mus.), a musical composition.
opye noun Opium.