flea

noun

ˈflē 

: 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

see also:

flea in one's ear

Illustration of flea

Examples of flea in a Sentence

Recent Examples on the Web

The pandemic probably began with fleas that bit rodents in Africa, and the disease raced along trade routes, killing up to 100 million people. — Jen Christensen, CNN Money, 8 Oct. 2026

Finally, pneumonic plague occurs when the bacterium infects the lungs—typically through inhalation of infectious droplets rather than flea bites. — Claire Maldarelli, Scientific American, 7 Oct. 2026

Plague is an infectious disease caused by the bacteria Yersinia pestis, usually found in small mammals and their fleas, WHO said. — Don Sweeney, Sacbee.com, 6 Oct. 2026

Plague outbreaks in the Middle Ages killed millions, due to widespread, common flea and rat infestations and less understanding of how to prevent disease from spreading. — News Editor, CBS News, 6 Oct. 2026

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

Phrases Containing flea

• beach flea
• fit as a flea
• flea beetle
• flea-bitten
• flea collar
• flea-flicker
• flea in one's ear
• flea market
• jigger flea
• sand flea
• water flea

Rhymes for flea

• be
• bee
• bree
• cree
• fee
• flee
• free
• gee
• ghee
• glee
• he
• ki

Kids Definition

flea

noun

ˈflē 

: any of an order of small wingless bloodsucking insects with a hard body and legs used for leaping

Medical Definition

flea

noun

ˈflē 

: 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, chigoe sense 1, dog flea, rat flea, sand flea, sticktight flea