Anus

·noun The posterior opening of the alimentary canal, through which the excrements are expelled.

anus
ānus, i, m. [for as-nus; cf. Sanscr. ās, = to sit, seat one's self; ἧμαι (Dor. ἧσμαι) κάθ-ημαι, Varr...

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.
anus
ānus (1) ī, m AS-.—Prop., a ring ; hence, the fundament . ...

An Elementary Latin Dictionary