Gádfly. n.s. [gad and fly; but by Skinner, who makes it the original of gad, goadfly. Supposed to be originally from goad, in Saxon ʒad, and fly.] A fly that when he stings the cattle make them gad or run madly about; the breese.
The fly called the gadfly breedeth of somewhat that swimeth upon the top of the water, and is most about ponds. Bac.
Light fly his slumbers, if perchance a flight
Of angry gadflies fasten on the herd. Thomson's Summer.