Illustration of mastiff
: 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
Examples of mastiff in a Sentence
Recent Examples on the Web
Like that dutiful mastiff, this Urus is happiest when let off the leash.
—
Bryan Hood,
Robb Report,
17 June 2026
Meanwhile, in 2004, a Neapolitan mastiff broke the Guinness World Record for most puppies after giving birth to 24.
—
Gabrielle Rockson,
PEOPLE,
1 May 2026
Four chihuahuas were compared against three large dogs, a Tibetan mastiff, a Newfoundland and an English mastiff, along with their owner in the room.
—
Kate Perez,
USA Today,
5 Mar. 2026
Cane Corsos are part of the mastiff family.
—
David Goodhue,
Miami Herald,
17 Feb. 2026
See All Example Sentences for mastiff
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Bryan Hood,
Robb Report,
17 June 2026
Meanwhile, in 2004, a Neapolitan mastiff broke the Guinness World Record for most puppies after giving birth to 24.
—
Gabrielle Rockson,
PEOPLE,
1 May 2026
Four chihuahuas were compared against three large dogs, a Tibetan mastiff, a Newfoundland and an English mastiff, along with their owner in the room.
—
Kate Perez,
USA Today,
5 Mar. 2026
Cane Corsos are part of the mastiff family.
—
David Goodhue,
Miami Herald,
17 Feb. 2026
See All Example Sentences for mastiff
Cite this Entry
“Mastiff.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/mastiff. Accessed 6 Jul. 2026.
Copy CitationKids Definition
mastiff
noun
mas·tiff
ˈmas-təf 
: any of a breed of large powerful smooth-coated dogs often used as watchdogs and guard dogs
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