Lewis Short
adversÄtrix | advor- (noun F) : (archaic ), , adversator
* A female antagonist or adversary (in Plaut. and Ter., and then again in Tert.): nunc assentatrix, dudum advorsatrix,Plaut. Most. 1, 3, 100; Ter. Heaut. 5, 3, 4; Tert. de Anim. 31: quin tu in ea re mihi fueris advorsatrix.
Charlton T. Lewis, Charles Short, A Latin Dictionary