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

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

Collies are more exposed to overbite than other pups, while boxers, Great Danes, mastiffs, and bulldogs are at risk of developing gingival hyperplasia, which is an overgrowth or thickening of the gums. —Matt Robison, Newsweek, 20 Nov. 2024

Other dogs listed by the American Kennel Club as the best guardians include the Rottweiler, most shepherd dogs, the Staffordshire bull terrier, volpino Italiano, and Tibetan mastiff among others. —Marco Rubio, Newsweek, 1 Nov. 2024

The Tibetan mastiff is often considered the most expensive dog since the breed has sold for up to millions of dollars. —Olivia Munson, USA TODAY, 17 Aug. 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