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
Cane Corsos, an ancient Italian mastiff breed, are renowned for their sheer size and protective instincts.
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Melissa Fleur Afshar, MSNBC Newsweek, 2 Sep. 2025
Deebo weighs 115 pounds and is a mix of American pit bull, St. Bernard, Great Dane and mastiff, Pitlanish said.
—Eric D. Lawrence, USA Today, 12 Aug. 2025
His 150-pound Pitbull mastiff needs to be housed somewhere.
—Emily Temple
may 27, Literary Hub, 27 May 2025
The couple had left their two mastiffs, Drago and Lita, at home with a pet sitter.
—Lauren Penington, Denver Post, 19 May 2025
See All Example Sentences for mastiff
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Melissa Fleur Afshar, MSNBC Newsweek, 2 Sep. 2025
Deebo weighs 115 pounds and is a mix of American pit bull, St. Bernard, Great Dane and mastiff, Pitlanish said.
—Eric D. Lawrence, USA Today, 12 Aug. 2025
His 150-pound Pitbull mastiff needs to be housed somewhere.
—Emily Temple
may 27, Literary Hub, 27 May 2025
The couple had left their two mastiffs, Drago and Lita, at home with a pet sitter.
—Lauren Penington, Denver Post, 19 May 2025
See All Example Sentences for mastiff
Cite this Entry
“Mastiff.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/mastiff. Accessed 9 Sep. 2025.
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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