Either
Part of speech: determiner
Definition: one or the other (of two) each of two
Part of speech: adverb
Definition: as well
Part of speech: pronoun
Definition: Both (people or things). One or other of two people or things.
Part of speech: conjunction
Definition: Introduces the first of two options, the second of which is introduced by "or".
Whether
Part of speech: conjunction
Definition: Used to introduce an interrogative content clause (indirect question) that consists of multiple alternative possibilities, and indicate uncertainty between them; if.Used to introduce a yes-or-no interrogative content clause (indirect question) that consists of a single possibility, and indicate uncertainty over it; if, whether or not.Used to introduce multiple alternative possibilities, and indicate the irrelevance of which is the case; regardless of whether, no matter whether.