<p><strong>Adjective</strong></p><ul><li>one or the other of two: You may sit at either end of the table.</li><li>each of two; the one and the other: There are trees on either side of the river.</li></ul><p><strong>Pronoun</strong></p><ul><li>one or the other: There are two roads into the town, and you can take either.</li><li>Either will do.</li></ul><p><strong>Conjunction</strong></p><ul><li>(a coordinating conjunction that, when preceding a word or statement followed by the disjunctive or, serves to emphasize the possibility of choice): Either come or write.</li></ul><p><strong>Adverb</strong></p><ul><li>also; too; as well; to the same degree (used after negative clauses coordinated by and, or, or nor, or after negative subordinate clauses): He's not fond of parties, and I'm not either.</li><li>If you don't come, she won't come either.</li></ul>