Webster's Revised Unabridged Dictionary · 1913

Whether

Whether , pronoun

[Old English whether, Anglo-Saxon hwa{not transcribed}er; akin to Old Saxon hwe{not transcribed}ar, OFries. hweder, Old High German hwedar, wedar, German weder, conj., neither, Icelandic hvārr whether, Gothic hwa{not transcribed}ar, Lithuanian katras, Latin uter, Greek {not transcribed}, {not transcribed}, Sanskrit katara, from the interrogatively pronoun, in Anglo-Saxon hwā who. {not transcribed}. See Who, and compare Either, Neither, Or, conj.]

Which (of two); which one (of two); -- used interrogatively and relatively. [Archaic]
Now choose yourself whether that you liketh. — Chaucer
One day in doubt I cast for to compare Whether in beauties' glory did exceed. — Spenser
Whether of them twain did the will of his father? — Matt. xxi. 31

Whether , conjunction

In case; if; -- used to introduce the first or two or more alternative clauses, the other or others being connected by or, or by or whether. When the second of two alternatives is the simple negative of the first it is sometimes only indicated by the particle not or no after the correlative, and sometimes it is omitted entirely as being distinctly implied in the whether of the first.
And now who knows But you, Lorenzo, whether I am yours? — Shakespeare
You have said; but whether wisely or no, let the forest judge. — Shakespeare
For whether we live, we live unto the Lord; and whether we die, we die unto the Lord; whether we live therefore, or die, we are the Lord's. — Rom. xiv. 8
But whether thus these things, or whether not; Whether the sun, predominant in heaven, Rise on the earth, or earth rise on the sun,... Solicit not thy thoughts with matters hid. — Milton
Collocations (2)
Whether or no , in either case; in any case; as, I will go whether or no.
Whether that , whether. — Shakespeare