"state of being depraved, corruption, degeneracy," 1640s; see deprave + -ity. Earlier in same sense was pravity. In theology, "hereditary tendency of humanity to commit sin" (1757).
Entries linking to depravity
deprave v.
late 14c., depraven, "corrupt, lead astray, pervert," from Old French depraver "to pervert; accuse" (14c.) and directly from Latin depravare "distort, disfigure;" figuratively "to pervert, seduce, corrupt," from de- "completely" (see de-) + pravus "crooked," which is of unknown etymology. Related: Depraved; depraving.
-ity
word-forming element making abstract nouns from adjectives and meaning "condition or quality of being ______," from Middle English -ite, from Old French -ete (Modern French -ité) and directly from Latin -itatem (nominative -itas), suffix denoting state or condition, composed of -i- (from the stem or else a connective) + the common abstract suffix -tas (see -ty (2)).
Roughly, the word in -ity usually means the quality of being what the adjective describes, or concretely an instance of the quality, or collectively all the instances; & the word in -ism means the disposition, or collectively all those who feel it. [Fowler]
pravity n.
"depravity, evil or corrupt state, wickedness," 1540s, from Latin pravitas "crookedness, distortion, deformity; impropriety, perverseness," from pravus "wrong, bad," literally "crooked," a word of unknown etymology.