Lewis Short
răbŭla (noun M) : 1. rabo
* A brawling, wrangling advocate, a pettifogger (cf.: clamator, declamator): non declamatorem aliquem de ludo aut rabulam de foro ... quaerimus,Cic. Or. 15, 47; with causidicus and proclamator, id. de Or. 1, 46. 202; with latrator, Quint. 12, 9, 12; cf. Fest. s. v. rava vox, p. 137 Müll.; Non. 26, 21; 60, 19.
Charlton T. Lewis, Charles Short, A Latin Dictionary