flea

UK: /ˈfliː/ US: /fli/ ,(flē)

WordReference Random House Learner's Dictionary of American English © 2025

flea /fli/   n. [countable]

1. Insects a small, wingless, bloodsucking insect, noted for its ability to leap.

WordReference Random House Unabridged Dictionary of American English © 2025

flea  (flē), n. 

1. Insects any of numerous small, wingless bloodsucking insects of the order Siphonaptera, parasitic upon mammals and birds and noted for their ability to leap.
2. Insects either of two common fleas of the genus Ctenocephalides, the very small, black C. felis (cat flea) or the similar but larger C. canis (dog flea,) both of which infest cats, dogs, and occasionally humans.
3. Insects, Invertebrates any of various small beetles and crustaceans that leap like a flea or swim in a jumpy manner, as the water flea and beach flea.
4. Idioms flea in one's ear:
   • a disconcerting rebuke or rebuff:
     The next time he shows his face around here he'll get a flea in his ear.
   • a broad hint.

• bef. 900; Middle English fle, Old English flēah, flēa; cognate with German Floh; akin to flee

Collins Concise English Dictionary © HarperCollins Publishers::

flea / fliː/ noun

1. any small wingless parasitic blood-sucking insect of the order Siphonaptera, living on the skin of mammals and birds and noted for its power of leaping
2. any of various invertebrates that resemble fleas, such as the water flea and flea beetle
3. flea in one's ear ⇒ a sharp rebuke

Etymology: Old English flēah; related to Old Norse flō, Old High German flōh