1911 Encyclopædia Britannica/Gnat

GNAT (O. Eng. gnæt), the common English name for the smaller dipterous flies (see Diptera) of the family Culicidae, which are now included among “mosquitoes” (see Mosquito). The distinctive term has no zoological significance, but in England the “mosquito” has commonly been distinguished from the “gnat” as a variety of larger size and more poisonous bite.