non

Non is a prefix meaning not or without, attached to adjectives, nouns, and verbs to create their negatives: nonfiction, nonsmoker, nonviolent, nonprofit.

Unlike un- or in-, non- typically creates neutral opposites rather than suggesting failure or deficiency—a nonbeliever simply doesn't believe, without the judgment that unbeliever might carry.

Standing alone, non functions as an adjective meaning not the real thing: The jeweler confirmed the diamond was a non.