1. a small or minute two-winged fly that forms swarms and breeds near water or marshy areas.
▪ used in names of other small flies whose larvae can be pests of plants, typically producing galls or damaging leaves.
2. a small person.informal
Word OriginOld Englishmycg(e), of Germanic origin; related to Dutch mug and German Mücke, from an Indo-European root shared by Latin musca and Greek muia ‘fly’.