Definition of maggot fly in US English:

maggot fly

noun

  • 1A blowfly, especially one of the genus Lucilia.

  • 2A fly whose larvae attack roots, especially the cabbage root fly, Delia radicum (Hylemya brassicae) (family Anthomyiidae).

Origin

Early 17th century; earliest use found in Samuel Gardiner (fl. 1606).