supererogo

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

sŭpĕr-ērŏgo, āvi, 1, v. a.,

to spend or pay out over and above : si quid forte supererogasti, Cod. Just. 2, 19, 14; Vulg. Luc. 10, 35.