• Choose a category
• All
• Classic-Fiction

1operative adjective 1 : producing an appropriate effect

2 : engaged in some form of operation : OPERATING

3 : having to do with physical operations; also : WORKING

4 : based on or consisting of an operation <~ dentistry>

2operative noun 1 : OPERATOR

2 a : a secret agent

b : a person not a member of a police force who is licensed to do detective work

Synonyms

detective, investigator, shadow, sleuth, tail—more at DETECTIVE

op·er·et·ta noun [ORIGIN: It, dim. of opera opera]

: a light musical-dramatic work with a romantic plot, spoken dialogue, and dancing scenes

oph·thal·mic adjective [ORIGIN: Gk ophthalmikos, fr. ophthalmos eye]

: of, relating to, or located near the eye

oph·thal·mol·o·gy noun : a branch of medicine dealing with the structure, functions, and diseases of the eye

— oph·thal·mol·o·gist noun

oph·thal·mo·scope noun : an instrument for use in viewing the interior of the eye and esp. the retina

1opiate noun 1 : a preparation or derivative of opium

2 : a narcotic or a substance with similar activity

2opiate adjective : inducing sleep : NARCOTIC

Synonyms

drowsy, hypnotic, narcotic, slumberous—more at HYPNOTIC

opine verb opined; opin·ing : to express an opinion

Synonyms

comment, note, observe, remark—more at REMARK

opin·ion noun 1 : a belief stronger than impression and less strong than positive knowledge

2 : JUDGMENT

3 : a formal statement by an expert after careful study

Synonyms

[1] belief, conviction, eye, feeling, judgment, mind, notion, persuasion, sentiment, verdict, view; also say; impression, perception, take; attitude; assumption, presumption, presupposition; conclusion, decision, determination; deliverance, esteem, estimate, estimation; credence, credit, faith; concept, conception, idea, thought; position, stand; comment, observation, reflection, remark; conjecture, guess, hunch, hypothesis, surmise, theory; advice, recommendation, suggestion; angle, outlook, perspective, point of view, slant, standpoint, viewpoint

[3] conclusion, decision, deliverance, determination, diagnosis, judgment, resolution, verdict—more at DECISION

opin·ion·at·ed adjective : obstinately adhering to personal opinions

Synonyms

dogged, hardheaded, headstrong, mulish, obdurate, obstinate, peevish, pertinacious, perverse, pigheaded, stubborn, unyielding, willful—more at OBSTINATE

opi·um noun [ORIGIN: ME, fr. L, fr. Gk opion, fr. dim. of opos sap]

: an addictive narcotic drug that is the dried latex of a Eurasian poppy

opos·sum noun, plural opossums also opossum : an omnivorous tree-dwelling No. American marsupial that is active chiefly at night and has a pointed snout and a prehensile tail

opp abbreviation opposite

op·po·nent noun : one that opposes : ADVERSARY

Synonyms

adversary, antagonist, rival; also equal, match; enemy, foe; archenemy, nemesis; competitor, contestant; bane, bête noire, curse; assailant, combatant, invader

op·por·tune adjective [ORIGIN: ME, fr. MF opportun, fr. L opportunus, fr. ob- toward + portus port, harbor]

: SUITABLE

— op·por·tune·ly adverb

op·por·tun·ism noun : a taking advantage of opportunities or circumstances esp. with little regard for principles or ultimate consequences

— op·por·tun·ist noun

— op·por·tu·nis·tic adjective

op·por·tu·ni·ty noun, plural -ties 1 : a favorable combination of circumstances, time, and place

2 : a chance for advancement

Synonyms

chance, occasion, opening, room; also break; play, way; juncture, pass

op·pose verb op·posed; op·pos·ing 1 : to place opposite or against something (as to provide resistance or contrast)

2 : to strive against : offer resistance to

— op·po·si·tion noun

Synonyms

buck, defy, fight, repel, resist, withstand—more at RESIST

battle, combat, contend, counter, fight—more at FIGHT

1opposite adjective 1 : set over against something that is at the other end or side

2 : OPPOSED, HOSTILE; also : CONTRARY

3 : contrarily turned or