petro
From LSJ
Latin > English (Lewis & Short)
pē̆tro: ōnis, m. 1. petra.
I A rustic: petrones rustici fere dicuntur, etc., Fest. p. 206, 23 Müll.; cf.: petrones rustici a petrarum asperitate et duritiā dicti, Paul. ex Fest. p. 207, 6 ib.—
II An old wether, whose flesh is as hard as a stone (anteclass.), Plaut. Capt. 4, 2, 40.