certain

certain

adjective

Definition of CERTAIN

1

known but not named <a certain person told me that today is your birthday>

Synonyms anonymous, given, one, some, unidentified, unnamed, unspecified

Related Words particular, specific

Near Antonyms known, named, specified

2

having or showing a mind free from doubt <I'm certain that they'll arrive on time>

Synonyms assured, clear, cocksure, confident, doubtless, implicit, positive, sanguine, sure

Related Words self-assured, self-conceited, self-confident; decisive, resolute, unfaltering, unhesitating, unquestioning, unwavering

Near Antonyms hesitant, indecisive, vacillating, wavering; diffident, unassuming

Antonyms doubtful, dubious, uncertain, unsure

3

having been established and usually not subject to change <a certain percentage of the profits will go to charity>

Synonyms certain, determinate, final, firm, flat, frozen, hard, hard-and-fast, inexpugnable, set, settled, stable

Related Words nonadjustable, noncancelable, nonnegotiable, unchangeable; constant, steady, unchanging, uniform, unwavering; definite, exact, explicit, specific; given, stated, stipulated; dependable, good, reliable, responsible, safe, solid, sure, tried, tried-and-true, true, trustworthy, trusty

Near Antonyms adjustable, changeable, negotiable; indefinite, open-ended, unspecified; capricious, changeful, flickery, fluctuating, fluid, inconstant, mercurial, mutable, temperamental, uncertain, unpredictable, unsettled, unstable, unsteady, variable, volatile

4

impossible to avoid or evade <as he got older, the athlete began to feel the certain effects of the aging process on his body>

Synonyms certain, ineluctable, ineludible, inescapable, necessary, sure, unavoidable, unescapable

Related Words decided, definite, settled; likely, possible, probable; destined, fated, foreordained, predestined, predetermined, preordained; inexorable, relentless, unremitting, unstoppable

Near Antonyms preventable (also preventible); doubtful, dubious, questionable, shaky, unclear; undecided, unsettled; undependable, unreliable; improbable, unlikely

Antonyms avoidable, evadable, uncertain, unsure

5

not likely to fail <chicken soup is grandma's certain cure for pretty much whatever ails you>

Synonyms can't-miss, certain, fail-safe, sure, surefire, unfailing

Related Words dependable, reliable; deadly, unerring

Near Antonyms doubtful, questionable, uncertain

Antonyms fallible

6

not capable of being challenged or proved wrong <up to this point there's been no certain evidence that a crime has been committed>

Synonyms accomplished, certain, inarguable, incontestable, incontrovertible, indisputable, indubitable, irrefragable, positive, sure, unanswerable, unarguable, unchallengeable, undeniable, unquestionable

Related Words unambiguous, unequivocal; absolute, clear, conclusive, decisive, definite, hands-down; uncontested, uncontradicted, undisputed, unquestioned

Near Antonyms controversial, debated, disputed; doubtful, dubious, iffy, inconclusive, indecisive, uncertain; ambiguous, equivocal; academic (also academical), hypothetical, speculative, theoretical (also theoretic)

Antonyms answerable, arguable, contradictable, controvertible, debatable, disputable, doubtable, moot, negotiable, problematic (also problematical), questionable, refutable