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mastiff vs. bullmastiff

[mas-tif, mah-stif] / ˈmæs tɪf, ˈmɑ stɪf /

noun

  1. one of a breed of large, powerful, short-haired dogs having an apricot, fawn, or brindled coat.

[bool-mas-tif, -mah-stif] / ˈbʊlˈmæs tɪf, -ˈmɑ stɪf /
Or bull-mastiff,

noun

  1. one of an English breed of dogs having a short, fawn or brindled coat, produced by crossing the bulldog and the mastiff.