(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).
–pronoun Archaic.
4.
which or whichever (of two)?
—Idiom
5.
whether or no, under whatever circumstances; regardless: He threatens to go whether or no.
[Origin: bef. 900; ME; OE hwether, hwæther, equiv. to hwe- (base of hwāwho) + -ther comp. suffix; c. ON hvatharr, Goth hwathar]
O.E. hwæðer, hweðer "which of two, whether," from P.Gmc. *khwatharaz (cf. O.S. hwedar, O.N. hvarr, Goth. huaþar, O.H.G. hwedar "which of the two," Ger. weder "neither"), from interrogative base *khwa- "who" (see who) + comparative suffix *-theraz (cf. Skt. katarah, Avestan katara-, Gk. poteros, L. uter "which of the two, either of two," Lith. katras "which of the two," O.C.S. koteru "which"). Its comparative form is either.
Ei"ther\ (?; 277), a. & pron. [OE. either, aither, AS. ?g?er, ?ghw[ae]?er (akin to OHG. ?ogiwedar, MHG. iegeweder); [=a] + ge + hw[ae]?er whether. See Each, and Whether, and cf. Or, conj.]1. One of two; the one or the other; -- properly used of two things, but sometimes of a larger number, for any one. Lepidus flatters both, Of both is flattered; but he neither loves, Nor either cares for him. --Shak. Scarce a palm of ground could be gotten by either of the three. --Bacon. There have been three talkers in Great British, either of whom would illustrate what I say about dogmatists. --Holmes. 2. Each of two; the one and the other; both; -- formerly, also, each of any number. His flowing hair In curls on either cheek played. --Milton. On either side . . . was there the tree of life. --Rev. xxii. 2. The extreme right and left of either army never engaged. --Jowett (Thucyd).
Nei"ther\ (? or ?; 277), a. [OE. neiter, nother, nouther, AS. n[=a]w?er, n[=a]hw[ae]?er; n[=a] never, not + hw[ae]?er whether. The word has followed the form of either. See No, and Whether, and cf. Neuter, Nor.] Not either; not the one or the other. Which of them shall I take? Both? one? or neither? Neither can be enjoyed, If both remain alive. --Shak. He neither loves, Nor either cares for him. --Shak.