Variant

Part of speech: noun (n.)

Something which differs in form from another thing, though really the same; as, a variant from a type in natural history; a variant of a story or a word.

Part of speech: adjective (a.)

1. Varying in from, character, or the like; variable; different; diverse.

2. Changeable; changing; fickle. [Obs.] He is variant, he abit [abides] nowhere. Chaucer.