why's

[hwahyz, wahyz]

contraction of why is: Why's dinner so late?

Usage note

See contraction.

why

[hwahy, wahy]

adverb

for what? for what reason, cause, or purpose?: Why did you behave so badly?

conjunction

for what cause or reason: I don't know why he is leaving.
for which; on account of which (usually after reason to introduce a relative clause): the reason why he refused to go.
the reason for which: That is why he returned.

noun, plural whys.

a question concerning the cause or reason for which something is done, achieved, etc.: a child's unending hows and whys.
the cause or reason: the whys and wherefores of a troublesome situation.

interjection

(used as an expression of surprise, hesitation, etc., or sometimes a mere expletive): Why, it's all gone!

Origin of why

before 900; Middle English; Old English hwī, hwȳ, instrumental case of hwæt what; cognate with Old Norse hvī

Usage note

See reason.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for why's

why

adverb

1. for what reason, purpose, or cause?why are you here?
2. (used in indirect questions)tell me why you're here

pronoun

for or because of whichthere is no reason why he shouldn't come

noun plural whys

(usually plural) the reason, purpose, or cause of something (esp in the phrase the whys and wherefores)

interjection

an introductory expression of surprise, disagreement, indignation, etcwhy, don't be silly!

Word Origin for why

Old English hwī; related to Old Norse hvī, Gothic hveileiks what kind of, Latin quī

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for why's

why

Old English hwi, instrumental case (showing for what purpose or by what means) of hwæt (see what), from Proto-Germanic *khwi (cf. Old Saxon hwi, Old Norse hvi), from PIE *qwei, locative of *qwo- "who" (cf. Greek pei "where"). As an interjection of surprise or to call attention to a statement, recorded from 1510s.