mastiff

Mastiff comes from Middle English mastif or mastyf, an irregular form influenced by Old French mestif, ultimately from Old French mastin, from Vulgar Latin *mansuetinus meaning 'tamed animal,' from Latin mansuetus, 'tamed.'

A word rooted in the idea of taming came to name one of the most imposing and powerful dog breeds, its origins in gentleness now overshadowed by its reputation for size and strength.

It shares its French ancestor, Old French mastin, with modern French mâtin, another word for a large dog.