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

And there's a tiny goldfish in there, just doing his best to control this big, goofy mastiff body. —Arika Herron, Axios, 3 Feb. 2025

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

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