1In classical mythology: a female demon or evil spirit associated with the goddess Hecate, supposed to eat humans and to be capable of appearing in different forms. Also more generally: an evil spirit, a hobgoblin; a phantom.
rare (In form Empusa) a genus of fungi which grow within the bodies of flies and other insects, causing deformity and death; (also empusa) a fungus of this genus. See also compounds 1.
Late 16th century; earliest use found in Robert Harrison (d. c1585), Brownist and writer. From post-classical Latin Empusa from ancient Greek Ἔμπουσα kind of hobgoblin, assuming various shapes, said to be sent by Hecate, of unknown origin; partly via Middle French, French empuse.