water flea

noun

: any of various small active dark or brightly colored aquatic crustaceans (such as a daphnia or cyclops)

Examples of water flea 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.
Zebra and quagga mussels, spiny water flea and dozens of other Eurasian organisms colonized the Great Lakes starting in the late 1900s after arriving in ballast water from transoceanic ships. Christine Keiner, The Conversation, 28 Feb. 2025 Water from ponds or other stagnant bodies of water can contain tiny crustaceans commonly known as water fleas, which in turn can be infected with Guinea worm larvae, according to the Centers for Disease Control and Prevention (CDC). Mary Kekatos, ABC News, 31 Dec. 2024 In 2019, the biologists finally arrived at the optimal formula of mysid shrimp, water fleas and blood worms. Alexander Nazaryan, New York Times, 9 May 2024 Birdseed and the plants that attract songbirds aren’t a big draw for waterfowl, as most prefer beetles, snails, water fleas and other insects found on the edges of lakes and ponds. Renee Elder, Charlotte Observer, 31 Jan. 2024 See All Example Sentences for water flea

Word History

First Known Use

1687, in the meaning defined above

Time Traveler
The first known use of water flea was in 1687

Browse Nearby Words

Cite this Entry

“Water flea.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/water%20flea. Accessed 4 Mar. 2025.

Kids Definition

water flea

noun
: any of various small active dark or brightly colored freshwater crustaceans (as a daphnia)

More from Merriam-Webster on water flea

Last Updated: - Updated example sentences
Love words? Need even more definitions?

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