mastiff

noun

mas·​tiff ˈma-stəf 

: any of a breed of very large massive powerful smooth-coated dogs that are apricot, fawn, or brindle and are often used as guard dogs

Illustration of mastiff

Examples of mastiff in a Sentence

Recent Examples on the Web

The viral clip shows the mastiff puppy's courageous first steps toward befriending the Labrador—her new sibling—resulting in a moment of gentle companionship that has resonated deeply with viewers on the app. —Michael Gfoeller and David H. Rundell, Newsweek, 15 Jan. 2025

His oxygen tank sat at his knees like an obedient mastiff. —Brandon Taylor, The Atlantic, 4 Jan. 2025

Hearts Melt Over Girl's Bond With Puppy By Melissa Fleur Afshar Life and Trends Reporter 0 The heartwarming bond between a Pennsylvania girl and her 200-pound English mastiff has melted the hearts of viewers online. —Dan Perry, Newsweek, 2 Jan. 2025

Retriever Gives Birth to Rare Litter of Puppies Containing Each Color of Lab While the Guinness Book of World Records lists the largest dog litter as a 24-pup litter born to a Neapolitan mastiff named Tia in 2004, Swartz believes Roxy's litter might be the largest for a Labrador retriever. —Kelli Bender, People.com, 11 Dec. 2024

Word History

Etymology

Middle English mastif, from Medieval Latin mastivus, from Vulgar Latin *masuetivus, from Latin mansuetus tame — more at mansuetude

First Known Use

14th century, in the meaning defined above

Kids Definition

mastiff

noun

mas·​tiff ˈmas-təf 

: any of a breed of large powerful smooth-coated dogs often used as watchdogs and guard dogs