From Longman Dictionary of Contemporary Englishfleaflea /fliː/ noun [countable] 1 HBIa very small insect without wings that jumps and bites animals and people to eat their blood Are you sure the dog has fleas?2 → send somebody off with a flea in their ear
Examples from the Corpus
flea• Pets with heavy coats may have their hair clipped to increase comfort and control fleas.• But there are safe ways to ward off fleas.• Look for tiny specks of black dirt - these are the flea droppings.• A water flea that is starving in a crowded pond is the victim not of food shortage but of competition.Origin flea Old English 