The Collaborative International Dictionary of English v.0.48:
Drone fly \Drone" fly`\ (Zool.)
A dipterous insect (Eristalis tenax), resembling the drone
bee. See Eristalis.
[1913 Webster]
The Collaborative International Dictionary of English v.0.48:
Eristalis \E*ris"ta*lis\, n. [NL.] (Zo["o]l.)
A genus of dipterous insects whose young (called rat-tailed
larv[ae]) are remarkable for their long tapering tail, which
spiracles at the tip, and for their ability to live in very
impure and salt waters; -- also called drone fly. Eristic