Lewis Short
căballus (noun M) = καβάλλης: [perh. Celtic; hence Ital. cavallo, Fr. cheval, Engl. cavalry, cavalier, etc.; cf. cob, Germ. Gaul]
* An inferior riding- or pack-horse, a nag (poet. and in post-Aug. prose): tardus, Lucil. ap. Non. p. 86, 15; Varr. ib.: mediā de nocte caballum Arripit,his nag,Hor. Ep. 1, 7, 88; so id. S. 1, 6, 59; 1, 6, 103; id. Ep. 1, 18, 36; Juv. 10, 60; 11, 195; Sen. Ep. 87, 8; Petr. 117, 12; Dig. 33, 7, 15: Gorgoneus, jestingly for Pegasus,Juv. 3, 118.
* Prov.
* Optat ephippia bos piger, optat arare caballus, i.e. no one is content with his own condition, Hor. Ep. 1, 14, 43.
* Tamquam caballus in clivo, for one who walks wearily, Petr. 134, 2 (cf. Ov. R. Am. 394: principio clivi noster anhelat equus).
Charlton T. Lewis, Charles Short, A Latin Dictionary