Why

• POS: Interjection, Conjunction, Noun, Adverb

CIDE DICTIONARY

Why, adv. [OE. whi, why, AS. hwī, hw, instrumental case of hwā, hwæt; akin to Icel. hvī why, Dan. & Sw. hvi; cf. Goth. hw. . See Who.].

•  For what cause, reason, or purpose; on what account; wherefore; -- used interrogatively. See the Note under What, pron., 1.  [1913 Webster]

  "Turn ye, turn ye from your evil ways; for why will ye die, O house of Israel?"  [1913 Webster]
•  For which; on account of which; -- used relatively.  [1913 Webster]

  "No ground of enmity between us known
  Why he should mean me ill or seek to harm."  [1913 Webster]

  "Turn the discourse; I have a reason why
  I would not have you speak so tenderly."  [1913 Webster]
•  The reason or cause for which; that on account of which; on what account; as, I know not why he left town so suddenly; -- used as a compound relative.  [1913 Webster]

  "If her chill heart I can not move,
  Why, I'll enjoy the very love."  [1913 Webster]

  "The how and the why and the where."  [1913 Webster]

For why, because; why. See Forwhy. [Obs. or Colloq.]

Why, n. 

 A young heifer.  Grose.  [1913 Webster]

OXFORD DICTIONARY

Why, adv., int., & n.
--adv.
1 a for what reason or purpose (why did you do it?; I do not know why you came). b on what grounds (why do you say that?).
2 (prec. by reason etc.) for which (the reasons why I did it).
--int. expressing:
1 surprised discovery or recognition (why, it's you!).
2 impatience (why, of course I do!).
3 reflection (why, yes, I think so).
4 objection (why, what is wrong with it?).
--n. (pl. whys) a reason or explanation (esp. whys and wherefores).

Idiom

why so? on what grounds?; for what reason or purpose?

Etymology

OE hwi, hwy instr. of hw{aelig}t WHAT f. Gmc

THESAURUS

Why

Chinese puzzle, argument, baffling problem, brain twister, conundrum, crossword puzzle, crux, enigma, enigmatic question, excuse, explanation, floorer, for which, for why, from what cause, ground, how come, jigsaw puzzle, knot, knotty point, mind-boggler, mystery, mystification, nut to crack, on what account, perplexed question, perplexity, poser, pourquoi, pretense, pretext, problem, proof, puzzle, puzzlement, puzzler, question, question mark, rational ground, rationale, reason, reason for, reason why, riddle, sixty-four dollar question, stated cause, sticker, stumper, the big idea, the idea, the whatfor, the wherefore, the why, tough proposition, underlying reason, vexed question, what for, wherefore, whyever, whyfor

ROGET THESAURUS

Why

Affirmation

N affirmance, affirmation, statement, allegation, assertion, predication, declaration, word, averment, confirmation, asseveration, adjuration, swearing, oath, affidavit, deposition, avouchment, assurance, protest, protestation, profession, acknowledgment, legal pledge, pronouncement, solemn averment, solemn avowal, solemn declaration, remark, observation, position, saying, dictum, sentence, ipse dixit, emphasis, weight, dogmatism, dogmatics, asserting, declaratory, predicatory, pronunciative, affirmative, soi-disant, positive, certain, express, explicit, absolute, emphatic, flat, broad, round, pointed, marked, distinct, decided, confident, trenchant, dogmatic, definitive, formal, solemn, categorical, peremptory, unretracted, predicable, affirmatively, in the affirmative, with emphasis, ex-cathedra, without fear of contradiction, as God is my witness, I must say, indeed, i' faith, let me tell you, why, give me leave to say, marry, you may be sure, I'd have you to know, upon my word, upon my honor, by my troth, egad, I assure you, by jingo, by Jove, by George, troth, seriously, sadly, in sadness, in sober sadness, in truth, in earnest, of a truth, truly, perdy, in all conscience, upon oath, be assured, yes, I'll warrant, I'll warrant you, I'll engage, I'll answer for it, I'll be bound, I'll venture to say, I'll take my oath, in fact, forsooth, joking apart, so help me God, not to mince the matter, quoth he, dixi.