anus

ānus (1) ī, m

AS-.—Prop., a ring ; hence, the fundament .

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

Webster's Dictionary of the English Language