mastiff

noun mas·tiff \ ˈmas-təf \
Updated on: 14 Nov 2017

Definition 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

Recent Examples of mastiff from the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'mastiff.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Illustration of mastiff

Origin and Etymology of mastiff

Middle English mastif, from Medieval Latin mastivus, from Vulgar Latin *masuetivus, from Latin mansuetus tame — more at mansuetude


MASTIFF Defined for English Language Learners

mastiff

noun

Definition of mastiff for English Language Learners

  • : a type of large, powerful dog


MASTIFF Defined for Kids

mastiff

noun mas·tiff \ ˈma-stəf \

Definition of mastiff for Students

: a very large powerful dog with a smooth coat

Learn More about mastiff


Seen and Heard

What made you want to look up mastiff? Please tell us where you read or heard it (including the quote, if possible).

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

WORD OF THE DAY

of or relating to dancing

Get Word of the Day daily email!

Test Your Vocabulary

Star Wars Words Quiz

  • cu-jedi-training
  • The bounty portion of bounty hunters (such as Boba Fett) comes from a Latin word meaning
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
SCRABBLE® Sprint

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!