(·adj & ·pron) Each of two; the one and the other; both;
— formerly, also, each of any number.
II. Either (·adj & ·pron) One of two; the one or the other;
— properly used of two things, but sometimes of a larger number, for any one.
III. Either (·conj Either) precedes two, or more, coordinate words or phrases, and is introductory to an alternative. It is correlative to or.