definitive

1 being the most accurate and apparently thorough the definitive work on the attack on Pearl Harbor Synonyms authoritative, classic, classical, magisterial Related Words conclusive, decisive; approved, official, sanctioned; accurate, correct; complete, comprehensive, exhaustive, thorough

2 serving to put an end to all debate or questioning a definitive answer that put an immediate end to the discussion Synonyms absolute, clear, deciding, decisive, conclusive, lastRelated Words determinate, determinative, dispositive, hands-down, inarguable, incontestable, incontrovertible, indisputable, indubitable, irrefutable, unanswerable, undebatable, undeniable, undisputable, unquestionable; unchallenged, uncontested, undisputed; unambiguous, unequivocal; certain, definite, positive, sure; cogent, compelling, convincing, persuasive, tellingNear Antonyms debatable, disputable, doubtable, doubtful, moot, problematic (also problematical), questionable, refutable; ambiguous, equivocal; controversial, debated, disputedAntonyms inconclusive, indecisive, unclear

3 so clearly expressed as to leave no doubt about the meaning the insurance company's definitive statement on the types of surgical operations that are covered Synonyms clear-cut, definite, explicit, express, specific, unambiguous, unequivocal, univocalRelated Words avowed, declared, specified, stated; categorical (also categoric), complete, comprehensive, exhaustive, full; certain, sure, unmistakable; clear, distinct, lucid, well-defined; exact, precise; direct, literal, plain, simple, straightforward; comprehensible, intelligible, understandableNear Antonyms cryptic, dark, enigmatic (also enigmatical), obscure, unclear; imprecise, inaccurate, incorrect, inexact; incomprehensible, unintelligibleAntonyms implicit, implied, inferred; ambiguous, circuitous; equivocal, indefinite, inexplicit, unspecific, vague

4 constituting, serving as, or worthy of being a pattern to be imitated Dashiell Hammett's Sam Spade is often cited as the definitive hard-boiled private detective Synonyms archetypal (also archetypical), classic, model, exemplary, imitable, paradigmatic, quintessential, textbookRelated Words ideal, nonpareil, special, unique; absolute, flawless, impeccable, perfect; A-OK, A1, bang-up, banner, capital, choice, crackerjack, dandy, excellent, fabulous, fantastic, fine, first-class, first-rate, grand, great, groovy, jim-dandy, keen, marvelous (or marvellous), nifty, par excellence, prime, primo [slang], sensational, splendid, stellar, sterling, superb, superior, superlative, swell, terrific, tip-top, top, top-notch, unsurpassed, wizard [chiefly British], wonderful; exceptional, fancy, high-gradeNear Antonyms bad, low-grade, poor, substandard, unsatisfactory; atrocious, execrable, vile, wretched; deficient, disappointing, failed, inadequate, inferior; average, normal, ordinary, representative, typical; mediocre, second-class, second-rate