Lewis & Short

corbītus, a, um, adj. [corbis], with a scuttle, bower: navis, Lucil. ap. Non. p. 533, 18.
Hence, subst.: corbīta, ae, f., a slowsailing ship of burden: corbitae dicuntur naves onerariae, quod in malo earum summo pro signo corbes solerent suspendi, Paul. ex Fest. p. 37, 7 Müll.: corbita est genus navigii tardum et grande, Non. p. 533, 10; so * Cic. Att. 16, 6, 1; opp. celox, Plaut. Poen. 3, 1, 40; on account of its slow motion: homines spissigradissimos, Tardiores quam corbitae sunt in tranquillo mari, id. ib. 3, 1, 4.