Definition of fly:
(n) :
any
insect of the order
Diptera; characterized by having two wings, also called
true flies; especially, any of the insects of the family Muscidae, such as the common
housefly (other families of Diptera include
mosquitoes and
midges)
"birds of passage fly to warmer regions as it gets colder in winter."
"he's pretty fly for a white guy."