from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Any of an ancient breed of large strong dogs, probably originating in Asia and having a short, often fawn-colored coat.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. One of several large breeds of dog (such as bulldogs and Saint Bernards), often used as guard dogs
from the GNU version of the Collaborative International Dictionary of English
- n. A breed of large dogs noted for strength and courage. There are various strains, differing in form and color, and characteristic of different countries.
from The Century Dictionary and Cyclopedia
- n. A variety of dog of considerable antiquity.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. an old breed of powerful deep-chested smooth-coated dog used chiefly as a watchdog and guard dog
Middle English mastif, alteration (perhaps influenced by Old French mestif, mongrel) of Old French mastin, from Vulgar Latin *(canis) mānsuētīnus, tame (dog), from Latin mānsuētus, past participle of mānsuēscere, to tame : manus, hand; + suēscere, to accustom.(American Heritage® Dictionary of the English Language, Fourth Edition)
An aberrant derivation from Old French mastin (modern French mâtin), from Vulgar Latin *mansuetīnus ("tamed (animal)"), from Latin mansuetus ("tamed"). (Wiktionary)