Definition of "gadfly"
gadfly
noun
plural gadflies
Any dipterous (“two-winged”) insect or fly of the family Oestridae (commonly known as a botfly) or Tabanidae (horsefly), noted for irritating animals by buzzing about them, and biting them to suck their blood; a gadbee.
Quotations
He that made that ryme in jeſt, little conſidered what a gad-fly may doe in earneſt. It is ſmall wiſedome to contemne the ſmalleſt enemy; the gad-fly is a little creature, but ſome little creatures be ſtingers; […]
1593, Gabriel Harvey, Pierces Supererogation: Or A New Prayse of the Old Asse, London: […] Iohn Wolfe; republished as John Payne Collier, editor, Pierces Supererogation: Or A New Prayse of the Old Asse. A Preparative to Certaine Larger Discourses, Intituled Nashes S. Fame (Miscellaneous Tracts. Temp. Eliz. & Jac. I; no. 8), [London: [s.n.], 1870], page 147
The nomads of Africa are constrained to wander by the attacks of the gadfly, which drives the cattle mad, and so compels the tribe to emigrate in the rainy season and drive off the cattle to the higher sandy regions.
1841, R[alph] W[aldo] Emerson, “Essay I. History.”, in Essays, Boston, Mass.: James Munroe and Company, pages 18–19
Vengeful Hera transformed her [Io] into an animal (a beautiful cow), and imposed upon her the company of a gadfly to sting her continuously, thus forcing her to escape on an endless pilgrimage.
2005, Rafael Argullol, “Introduction”, in Yolanda Gamboa, transl., The End of the World as a Work of Art: A Western Story, Lewisburg, Pa.: Bucknell University Press; Cranbury, N.J.: Associated University Presses, page 48
(figuratively, also attributively)
A person or thing that irritates or instigates.
Quotations
VVhat gad flye tickles ſo this Macrinus, / That up flinging thy taile, he breakes thus from me.
1620 (first performance; published 1622), Philip Messenger [i.e., Philip Massinger], Thomas Dekker, The Virgin Martyr; a Tragedie. […], London: […] B[ernard] A[lsop] and T[homas] F[awcet] for Thomas Iones, […], published 1631, Act II
(specifically) A person who upsets the status quo by posing novel or upsetting questions, or attempts to stimulate innovation by being an irritant.
Quotations
What was required now was the intervention of some men who were not gadflies. […] The logic of [Charles] Pearson's arguments was accepted, up to a point, by a consortium of businessmen. In August 1854, […] the consortium obtained royal assent for […] the Metropolitan Railway. […] In 1859, when it looked as though the Metropolitan Railway Company would be wound up with no line built, he [Pearson] wrote a pamphlet: A Twenty Minutes Letter to the Citizens of London in Favour of the Metropolitan Railway and City Station. Gadfly he may have been, but by this 'letter' he persuaded the Corporation of London to invest £200,000 in the line, a most unusual example of a public body investing in a Victorian railway.
2012, Andrew Martin, “The World of Charles Pearson”, in Underground Overground: A Passenger’s History of the Tube, London: Profile Books, pages 26–27
Dr. [Carl] Hart, 54, the first tenured African-American science professor at Columbia, is a gadfly among drug researchers and a rock star among advocates for decriminalizing drugs.
2021 April 10, John Leland, “This heroin-using professor wants to change how we think about drugs”, in The New York Times, New York, N.Y.: The New York Times Company, archived from the original on 28 May 2022
Synonym of gadabout (“a person who restlessly moves from place to place, seeking amusement or the companionship of others”)
Quotations
[Y]our Harriet may turn gadfly, and never be eaſy but vvhen ſhe is forming parties, or giving vvay to them, that may make the home, that hitherto has been the chief ſcene of her pleaſures, undelightful to her.
1753 (indicated as 1754), [Samuel Richardson], “Letter XVIII. Miss Byron. In Continuation.”, in The History of Sir Charles Grandison. […], 2nd edition, volume I, London: […] S[amuel] Richardson; [a]nd sold by C. Hitch and L. Hawes, […], page 125