RhymeZone: undead definitions

Definitions of undead:

adjective: Pertaining to a corpse, though having qualities of life.
adjective: (horror fiction) Being animate, though non-living.
noun: (horror fiction) Those creatures which are undead; that is, dead yet still animate.
noun: (horror fiction) A creature that is undead; that is, dead but still animate.

(Definitions from Wiktionary)