Lewis Short
trĕpondo
* Neutr. indecl. [tres-pondus; cf. duapondo, under duo], three pounds: ejusdem radicis trepondo, panacis pondo IV.,Scrib. Comp. 165: adipis porcinae,id. ib. 271; cf. Quint. 1, 5, 15.
Charlton T. Lewis, Charles Short, A Latin Dictionary