mastiff

n type of large strong dog with drooping ears, often used as a watchdog 大驯犬.

mast, mast-head, mastectomy, mastemaster, master, master class, Master of Ceremonies, master sergeant, Master's degree (also Master's), master-key, master-stroke, masterful, masterfully, masterly, mastermind, masterpiece, mastery, mastic, masticate, mastication, mastitis, mastodon, mastoid, mastoiditis, masturbate, masturbation, masturbatory, mat, matador, match, match point, matchbox, matched, matchless, matchmaker, matchmaking, matchstick, matchwood, mate, material,