pygisiacus

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.

pȳgĭsĭăcus, a, um, adj. [πυγησιακός (not in use), from πυγή], qs.

of or belonging to secret buttock-worship : puellam invitare ad pygisiaca sacra, i. e. to copulation , Petr. S. 140 (al. pygiaca, pygiciaca, in the same signif.).