neither (Adjective) — Not either; not one or the other.
neither (Adverb) — After a negative statement used to indicate that the next statement is similarly negative. ex. "just as you would not complain, neither should he" ex. "I was not happy and neither were they"
neither (Pronoun) — Not one nor the other, not either. ex. "Do you like milk or sugar? Neither"
neither (Conjunction) — Used before two (or more) alternatives to indicate that they did not happen or are not true. ex. "Her daughter enjoyed a most uncommon degree of popularity for a woman neither young, handsome, rich, nor married" ex. "his hair was neither long nor short"