Any of numerous two-winged insects of the order Diptera, especially any of the family Muscidae. Examples of true flies are the house fly and the tsetse fly. The true flies (order Diptera) should not be confused with other insects that are called "flies", such as caddisfly, butterfly, and dragonfly, that belong to other insect orders.
FLY
Meaning of FLY in English
English glossary of entomology and crop protection. Английский глоссарий энтомологии и защиты растений. 2012