why

[hwahy, wahy]

adverb

1. for what? for what reason, cause, or purpose?.

   Why did you behave so badly?

conjunction

1. for what cause or reason.

   I don't know why he is leaving.

2. for which; on account of which (usually after reason to introduce a relative clause).

   the reason why he refused to go.

3. the reason for which.

   That is why he returned.

noun

plural

whys 

1. a question concerning the cause or reason for which something is done, achieved, etc..

   a child's unending hows and whys.

2. the cause or reason.

   the whys and wherefores of a troublesome situation.

interjection

1. (used as an expression of surprise, hesitation, etc., or sometimes a mere expletive).

   Why, it's all gone!

why

/ waɪ /

adverb

1. 1. for what reason, purpose, or cause?

      why are you here?

   2. ( used in indirect questions )

      tell me why you're here

pronoun

1. for or because of which

   there is no reason why he shouldn't come

noun

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

interjection

1. an introductory expression of surprise, disagreement, indignation, etc

   why, don't be silly!

Usage

See reason.

Word History and Origins

Origin of why¹

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

Word History and Origins

Origin of why¹

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

Example Sentences

Here’s why listing your home late in the year can still lead to strong offers.

Read more on The Wall Street Journal

It is not clear why the decision was made to expand the board of directors and how the individuals were selected.

Read more on Los Angeles Times

But the USA defender showcased exactly why Chelsea were willing to pay the big bucks with a colossal display against Europe's elite side.

Read more on BBC

So why - in an age where so many of us are feeling the financial pinch - are some of these budget shops that are household names having such a tough time?

Read more on BBC

We can’t know for certain if the Values Bridge data reveals a slow trend away from the centrality of family in the American psyche or a sudden drop, or why in either case.

Read more on The Wall Street Journal