black rat

noun

: a rat of the genus Rattus (R. rattus) that infests houses and has been the chief vector of bubonic plague

Browse Nearby Words

black quarter
black rat
black snakeroot
See all Nearby Words

Cite this Entry

“Black rat.” Merriam-Webster.com Medical Dictionary, Merriam-Webster, https://www.merriam-webster.com/medical/black%20rat. Accessed 6 May. 2025.

Copy Citation

Share

Love words? Need even more definitions?

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

Popular in Grammar & Usage

See More

'Affect' vs. 'Effect'

Words You Always Have to Look Up

How to Use Em Dashes (—), En Dashes (–) , and Hyphens (-)

Why is '-ed' sometimes pronounced at the end of a word?

Democracy or Republic: What's the difference?
See More

Popular in Wordplay

See More

Flower Etymologies For Your Spring Garden

Great Big List of Beautiful and Useless Words, Vol. 1

Rare and Amusing Insults, Volume 3

'Za' and 9 Other Words to Help You Win at SCRABBLE

More Words with Remarkable Origins
See More

Popular

See More

'Affect' vs. 'Effect'

Flower Etymologies For Your Spring Garden

Great Big List of Beautiful and Useless Words, Vol. 1
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Word Game Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
Missing Letter A daily crossword with a twist
chain-with-string
Fastest Quiz Ever: Missing Link Five seconds to figure out the word that fits bot...
See All