From The Collaborative International Dictionary of English v.0.48 :
no-see-um \no-see-um\ n. (Zool.)
Any of several minute two-winged biting insects of the family
Ceratopogonidae that suck the blood of mammals and birds
and other insects; also called biting midge and punkie.
Syn: punkie, punky, punkey, biting midge.
[WordNet 1.5]
From WordNet (r) 3.0 (2006) :
biting midge
n 1: minute two-winged insect that sucks the blood of mammals
and birds and other insects [syn: punkie, punky,
punkey, no-see-um, biting midge]