Why is the ninth month called September?
"depravity, infamy," late 15c., from Middle French turpitude (early 15c.), from Latin turpitudinem (nominative turpitudo) "baseness," from turpis "vile, ugly, base, shameful," used in both the moral and the physical senses; of unknown origin. Perhaps originally "what one turns away from" (cf. Latin trepit "he turns").