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
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But just reaching the elite, champions-only show is a major accomplishment in dogdom, especially for first-timers such as Joseph Carrero and his Neapolitan mastiff, Dezi.
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CBS News, 4 Feb. 2026
But just reaching the elite, champions-only show is a major accomplishment in dogdom, especially for first-timers such as Joseph Carrero and his Neapolitan mastiff, Dezi.
—Jennifer Peltz, Chicago Tribune, 3 Feb. 2026
Breeds commonly seen in Milwaukee – such as pit bull mixes, cane corsos and mastiffs – can’t tolerate more than 15 minutes in freezing weather.
—Quinn Clark, jsonline.com, 22 Jan. 2026
Jones, 1-year-old mastiff mix, #967270.
—Linda McIntosh, San Diego Union-Tribune, 22 Dec. 2025
See All Example Sentences for mastiff
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CBS News, 4 Feb. 2026
But just reaching the elite, champions-only show is a major accomplishment in dogdom, especially for first-timers such as Joseph Carrero and his Neapolitan mastiff, Dezi.
—Jennifer Peltz, Chicago Tribune, 3 Feb. 2026
Breeds commonly seen in Milwaukee – such as pit bull mixes, cane corsos and mastiffs – can’t tolerate more than 15 minutes in freezing weather.
—Quinn Clark, jsonline.com, 22 Jan. 2026
Jones, 1-year-old mastiff mix, #967270.
—Linda McIntosh, San Diego Union-Tribune, 22 Dec. 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 14 Feb. 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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