from
The Collaborative International Dictionary of English v.0.48
Flea \Flea\, n. [OE. fle, flee, AS. fle['a], fle['a]h; akin to
D. vtoo, OHG. fl[=o]h, G. floh, Icel. fl[=o], Russ. blocha;
prob. from the root of E. flee. [root]84. See {Flee}.]
(Zool.)
An insect belonging to the genus {Pulex}, of the order
{Aphaniptera}. Fleas are destitute of wings, but have the
power of leaping energetically. The bite is poisonous to most
persons. The human flea ({Pulex irritans}), abundant in
Europe, is rare in America, where the dog flea
({Ctenocephalides canis}, formerly {Pulex canis}) and the
smaller cat flea ({Ctenocephalides felis}) take its place.
See {Aphaniptera}, and {Dog flea}. See Illustration in
Appendix.
[1913 Webster]
{A flea in the ear}, an unwelcome hint or unexpected reply,
annoying like a flea; an irritating repulse; as, to put a
flea in one's ear; to go away with a flea in one's ear.
{Beach flea}, {Black flea}, etc. See under {Beach}, etc.
[1913 Webster]