7 letters · 15 points in Scrabble
noun an old breed of powerful deep-chested smooth-coated dog used chiefly as a watchdog and guard dog
originFrom Middle English mastif, mastyf, an aberrant derivation (with influence from Old French mestif) from Old French mastin (modern French mâtin), from Vulgar Latin *mansuetinus (“tamed (animal)”), from Latin mansuetus (“tamed”).
Etymology from Wiktionary, CC BY-SA 3.0