breeder

noun

breed·​er ˈbrē-dər How to pronounce breeder (audio)
: one that breeds: such as
a
: an animal or plant kept for propagation
b
: one engaged in the breeding of a specified organism
c
: a nuclear reactor designed to produce more fissionable material than it uses as fuel

called also breeder reactor

Examples of breeder in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The report also pointed to policy and regulatory gaps in seed guidelines, with weak connections between breeders and farmers. — Jennifer Bringle, Footwear News, 16 Oct. 2026 American breeders began registering Holstein pedigrees and maintaining herdbooks in the 1800s. — Encyclopedia Britannica, 7 Oct. 2026 But many breeders have included these species so that the resulting hybrids are more tolerant of heat and humidity. — Arricca Elin Sansone, Southern Living, 3 Oct. 2026 Some come for the entire summer season, as Big Horn is renowned for its top-quality horses, trainers and breeders. — Irene Middleman Thomas, Denver Post, 27 Sep. 2026 See All Example Sentences for breeder

Word History

First Known Use

1529, in the meaning defined above

Time Traveler
The first known use of breeder was in 1529

Rhymes for breeder

See All Rhymes for breeder

Browse Nearby Words

breed
breeder
Breede River yellowwood
See all Nearby Words

Cite this Entry

“Breeder.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/breeder. Accessed 27 Oct. 2026.

Copy Citation

Medical Definition

breeder

noun
breed·​er
: one that breeds: as
a
: an animal or plant kept for propagation
b
: one engaged in the breeding of a specified organism
Love words? Need even more definitions?

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

Last Updated: - Updated example sentences

More from Merriam-Webster

Word of the Day

Listen to the pronunciation of milieu

See Definitions and Examples »

Popular in Grammar & Usage

See More

How to Use 'Who' vs. 'Whom'

Merriam-Webster’s Great Big List of Words You Love to Hate

'Affect' vs. 'Effect'

'A' or 'an'? What about before 'h'? An Indefinite Article Guide

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

Popular in Wordplay

See More

The Longest Long Words List

9 Words That Sound Like Insults But Aren't

12 Lovely and Unusual Words for the Natural World

Why do we 'bury the lede?'

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

Popular

See More

How to Use 'Who' vs. 'Whom'

The Longest Long Words List

9 Words That Sound Like Insults But Aren't
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 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?
The Missing Letter A daily crossword with a twist
different halloween monsters in silhouette
A Monstrous Vocab Quiz Words That Go Bump in the Night
See All