reason

1 a statement given to explain a belief or act she gave a good reason for her seemingly suspicious behavior Synonyms account, accounting, argument, case, explanation, rationale Related Words alibi, apologia, apology, defense, excuse, justification, vindication; appeal, plea; guise, pretense (or pretence), pretext, rationalization

2 something (as a belief) that serves as the basis for another thing a firm belief that we are here on earth to help others is the reason for her tireless volunteer work Synonyms account, authority, grounds, motive, subject, wherefore, why Related Words antecedent, cause, consideration, impetus, incentive, inspiration, instigation, occasion, stimulus

3 an explanation that frees one from fault or blame what reason do you have for being in such a bad mood? Synonyms alibi, apology, defense, justification, plea, excuseRelated Words color, guise, pretense (or pretence), pretext, rationale, rationalization, vindication, whitewash; cop-out, out; acknowledgment (or acknowledgement), atonement, confession; extenuation, palliation

4 someone or something responsible for a result what's the meteorological reason for tornadoes? Synonyms antecedent, causality, causation, occasion, causeRelated Words consideration, determinant, factor; alpha and omega, be-all and end-all; impetus, incentive, inspiration, instigation, stimulus; mother, origin, root, source, springNear Antonyms ramification; denouement (also dénouement), repercussion; conclusion, end; by-product, side effect (also side reaction)Antonyms aftereffect, aftermath, consequence, corollary, development, effect, fate, fruit, issue, outcome, outgrowth, product, result, resultant, sequel, sequence, upshot

5 the ability to learn and understand or to deal with problems you'll need to use all of your reason to get out of this tight spot Synonyms brain(s), brainpower, gray matter, headpiece, intellect, intellectuality, mentality, intelligence, sense, smartsRelated Words eggheadedness, highbrowism, intellectualism; braininess, brilliance; acumen, alertness, apprehension, astuteness, discernment, discriminability, insight, judgment (or judgement), perception, percipience, perspicacity; common sense, horse sense, mother wit; aptitude, talent; sagacity, sapience, wisdom, wit; head, mind, skullNear Antonyms denseness, density, doltishness, dopiness, dullness (also dulness), dumbness, fatuity, feeblemindedness, foolishness, half-wittedness, idiocy, imbecility, senselessness, simpleness, slowness, stupidity

6 the normal or healthy condition of the mental abilities was afraid that with all the stress he was under, he'd lose all reason Synonyms daylights, head, marbles, mind, saneness, sanity, wit(s)Related Words rationality, reasonableness, sense; health, healthfulness, healthiness, wholesomeness; clearheadedness, lucidity, lucidness, normalcy, normality, soundness; wisdomNear Antonyms delusion, hallucination; delirium, frenzy, hysteriaAntonyms dementia, derangement, insanity, lunacy, madness, mania, unreason

7 the thought processes that have been established as leading to valid solutions to problems in a time of national crisis we need to listen to the voice of reason Synonyms intellection, ratiocination, logic, reasoning, senseRelated Words cogency, coherence, logicality, logicalness, rationality, rationalness; convincingness, persuasiveness; syllogism, synthesis; analysis, dissection; deduction, induction; argumentation, disputationNear Antonyms illogic, incoherence; absurdity, brainlessness, insanity, irrationality, nonsensicalness, preposterousness, senselessness