either >> /ˈiðər/
Definition: [conjunction & adverb] Used before the first of two (or occasionally more) alternatives that are being specified (the other being introduced by “or”)
Example: either I'll accompany you to your room, or I'll wait here
Definition: [conjunction & adverb] Used to indicate a similarity or link with a statement just made.
Example: You don't like him, do you? I don't either
Definition: [determiner & pronoun] One or the other of two people or things.
Example: there were no children of either marriage