Meaning of EITHER in English

EITHER

I. ˈē-thər also ˈī- adjective

Etymology: Middle English, from Old English ǣghwæther both, each, from ā always + ge-, collective prefix + hwæther which of two, whether — more at aye , co-

Date: before 12th century

1. : being the one and the other of two : each

flowers blooming on either side of the walk

plays either instrument well

2. : being the one or the other of two

take either road

II. pronoun

Date: before 12th century

: the one or the other

take either of the two routes

III. conjunction

Date: before 12th century

— used as a function word before two or more coordinate words, phrases, or clauses joined usually by or to indicate that what immediately follows is the first of two or more alternatives

can be used either as a guest room or as an office

IV. adverb

Date: 15th century

1. : likewise , moreover — used for emphasis after a negative

not smart or handsome either

2. : for that matter — used for emphasis after an alternative following a question or conditional clause especially where negation is implied

who answers for the Irish parliament? or army either ? — Robert Browning

Merriam-Webster's Collegiate English vocabulary.      Энциклопедический словарь английского языка Merriam Webster.