whether

UK: /ˈ^hwɛðə^r/ US: /ˈhwɛðɚ, ˈwɛð-/ ,(hweᵺ′ər, weᵺ′-)

WordReference Random House Learner's Dictionary of American English © 2025

wheth•er /ˈhwɛðɚ, ˈwɛð-/   conj. 

1. (used to introduce the first of two or more choices or possibilities;
   the second one is preceded by the word or:)
   I don't care whether we go or stay.
2. (used to introduce a single choice, while the second choice is understood or implied, to be the negation of the first):
   See whether she has come.

Idioms

3. whether or not or whether or no, under whatever circumstances;
   in any case;
   regardless:
   He tends to insist on his views whether or not the facts support them.

WordReference Random House Unabridged Dictionary of American English © 2025

wheth•er  (hweᵺ′ər, weᵺ′-), conj. 

1. (used to introduce the first of two or more alternatives, and sometimes repeated before the second or later alternative, usually with the correlative or):
   It matters little whether we go or stay. Whether we go or whether we stay, the result is the same.
2. (used to introduce a single alternative, the other being implied or understood, or some clause or element not involving alternatives):
   See whether or not she has come. I doubt whether we can do any better.
3. [Archaic.] (used to introduce a question presenting alternatives, usually with the correlative or).
4. whether or no, under whatever circumstances;
   regardless:
   He threatens to go whether or no.

pron. Archaic. 

5. which or whichever (of two)?

• bef. 900; Middle English; Old English hwether, hwæther, equivalent. to hwe- (base of hwā who) + -ther comparative suffix; cognate with Old Norse hvatharr, Gothic hwathar

Usage

See if. 

Collins Concise English Dictionary © HarperCollins Publishers::

whether / ˈwɛðə/ conjunction

1. (subordinating) used to introduce an indirect question or a clause after a verb expressing or implying doubt or choice in order to indicate two or more alternatives, the second or last of which is introduced by or or or whether: he doesn't know whether she's in Britain or whether she's gone to France
2. (coordinating)
   another word for either3: anyone, whether liberal or conservative, would agree with me
3. whether or no ⇒
   used as a conjunction as a variant of whether1
4. under any circumstances: he will be here tomorrow, whether or no
5. whether…or, whether…or whether ⇒ if on the one hand…or even if on the other hand: you'll eat that, whether you like it or not

Etymology: Old English hwæther, hwether; related to Old Frisian hweder, hoder, Old High German hwedar, Old Norse hvatharr, hvarr, Gothic hwathar