| n. | 1. | (Zool.) An insect that deposits its eggs in plants, and occasions galls, esp. any small hymenopteran of the genus Cynips and allied genera. See Illust. of Gall. |
| Noun | 1. | gallfly - small solitary wasp that produces galls on oaks and other plants |
| 2. | gallfly - fragile mosquito-like flies that produce galls on plants Synonyms: gall gnat, gall midge | |
| 3. | gallfly - any of various insects that deposit their eggs in plants causing galls in which the larvae feed |