'Lycanthropy' definitions:

Definition of 'lycanthropy'

noun

(folklore) the magical ability of a person to assume the characteristics of a wolf

From: GCIDE

Lycanthropy \Ly*can"thro*py\, n. [Gr. ?: cf. F. lycanthropie.]
1. The supposed act of turning one's self or another person into a wolf. --Lowell. [1913 Webster]
2. (Med.) A kind of erratic melancholy, in which the patient imagines himself a wolf, and imitates the actions of that animal. [1913 Webster] lycee