one of a breed of large, powerful, short-haired dogs having an apricot, fawn, or brindled coat.
Origin: 1300–50; ME mastif, perh. extracted from AF masti(n)s (taken as *mastifs), pl. of OF mastin < VL (canis) *ma(n)suētīnus, deriv. of L mansuētus tame, mild (see mansuetude)
mas·tiff (mās'tĭf) n. Any of an ancient breed of large strong dogs, probably originating in Asia and having a short, often fawn-colored coat.
[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; see man-2 in Indo-European roots + suēscere, to accustom; see s(w)e- in Indo-European roots.]
"large, powerful breed of dog," c.1330, from O.Fr. mastin or Prov. mastis, both from V.L. *mansuetinus "domesticated," from L. mansuetus "tame, gentle" (see mansuetude). Form infl. by O.Fr. mestif "mongrel."