either etymology

Middle English word either comes from English whether, English ay

Detailed word origin of either

Dictionary entryLanguageDefinition
whether English (eng) (obsolete) Which of two. [11th-19th c.] (obsolete) Which of two. (obsolete) Introducing a direct interrogative question (often with correlative or) which indicates doubt between alternatives.. Used to introduce a disjunctive adverbial clause which qualifies the main clause of the sentence (with correlative or).. Used to introduce an indirect interrogative question that consists of multiple [...]
ay English (eng) ("yes") (question tag) (archaic, poetic, _, or, _, Northern England) Always; ever; continually; for an indefinite time. ("yes"). Ah! alas!.
ǣġhwæþer Old English (ang)
either Middle English (enm) Both of two.. Each of two.. Either of two. Both, all, or any of a set.. Each of a group. Both of two members of a group.. Each of two members of a group.. Either of two members of a group.