GADFLY

gadfly

(noun) any of various large flies that annoy livestock

pest, blighter, cuss, pesterer, gadfly

(noun) a persistently annoying person

Source: WordNet® 3.1

Etymology

Noun

gadfly (plural gadflies)

Any dipterous insect of the family Oestridae, commonly known as botflies.

Synonym: botfly

Coordinate term: warble fly

A horsefly: any of various species of fly, of the family Tabanidae, noted for buzzing about animals and sucking their blood.

Synonyms: horsefly, stoat-fly, stout

Coordinate term: warble fly

(figurative) One who upsets the status quo by posing upsetting or novel questions, or attempts to stimulate innovation by proving an irritant.

(pejorative) One who merely irritates without making useful suggestions.

(derogatory, slang) A bloodsucker; a person who takes without giving back.

Synonyms: bloodsucker, Thesaurus:scrounger

Source: Wiktionary

Gad"fly`, n.; pl. Gadflies. Etym: [Gad + fly.] (Zoöl.)

Definition: Any dipterous insect of the genus Oestrus, and allied genera of botflies.

Note: The sheep gadfly (Oestrus ovis) deposits its young in the nostrils of sheep, and the larvæ develop in the frontal sinuses. The common species which infests cattle (Hypoderma bovis) deposits its eggs upon or in the skin where the larvæ or bots live and produce sores called wormels. The gadflies of the horse produce the intestinal parasites called bots. See Botfly, and Bots. The true horseflies are often erroneously called gadflies, and the true gadflies are sometimes incorrectly called breeze flies. Gadfly petrel (Zoöl.), one of several small petrels of the genus Oestrelata.

Source: Webster’s Unabridged Dictionary 1913 Edition