: any of an order (Siphonaptera) of small wingless bloodsucking insects that have a hard laterally compressed body and legs adapted to leaping and that feed on warm-blooded animals
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He was taken to the veterinarian first thing Monday morning, where he was treated for fleas and worms and partially cleaned up.—Alice Gibbs, MSNBC Newsweek, 1 Apr. 2026 Bites are similar to a mosquito or flea bite.—Fort Worth Star-Telegram, 30 Mar. 2026 If the canary wouldn’t sing, if the milkman was late, if the Pekingese had fleas, if an old coot in a starched collar had a heart attack on the way to church, that was the smog.—Patt Morrison, Los Angeles Times, 26 Mar. 2026 Petco Petco's best deals include 40% off first repeat delivery on select flea and tick items, along with buy three or more select dog/ cat treats and get 20% off.—Jessica Moore, USA Today, 25 Mar. 2026 See All Example Sentences for flea
Word History
Etymology
Middle English fle, from Old English flēa; akin to Old High German flōh flea
First Known Use
before the 12th century, in the meaning defined above
Time Traveler
The first known use of flea was
before the 12th century
: any of the order Siphonaptera comprising wingless bloodsucking insects that have a hard laterally compressed body and legs adapted to leaping and that feed on warm-blooded animals see cat flea, chigoesense 1, dog flea, rat flea, sand flea, sticktight flea