Lewis Short
gerro (noun M) : (archaic orthogr.: ‡ cerrones leves et inepti, Paul. ex Fest. v. p. 40 Müll.), , gerrae
* A trifler, idle fellow: gerro, iners, fraus, heluo, Ganeo, damnosus!Ter. Heaut. 5, 4, 10.
Charlton T. Lewis, Charles Short, A Latin Dictionary