MASTIFF /ˈmæstɪf/ Scrabble 15 Words With Friends 16 Scrabble letter values: M3A1S1T1I1F4F4 = 15 Definition noun an old breed of powerful deep-chested smooth-coated dog used chiefly as a watchdog and guard dog. See all 61 words you can make from MASTIFF → 7-letter words Words starting with M Words ending with F ← Unscramble different letters