Origin: Mastives is irregular and unusual] [Prob. Fr. Prov. E. Masty, adj, large, n, a great dog, prob. Fr. Mast fruit, and hence, lit, fattened with mast. There is perh. Confusion with OF. Mestif mongrel; cf. Also f. Matin mastiff, OF. Mastin.
(Science: zoology) a breed of large dogs noted for strength and courage. There are various strains, differing in form and colour, and characteristic of different countries.
(Science: zoology) mastiff bat, any bat of the genus Molossus; so called because the face somewhat resembles that of a mastiff.