Gnat

Gnat - (Easton's Bible Dictionary)

Only in Matt. 23:24, a small two-winged stinging fly of the genus Culex, which includes mosquitoes. Our Lord alludes here to the gnat in a proverbial expression probably in common use, "who strain out the gnat;" the words in the Authorized Version, "strain at a gnat," being a mere typographical error, which has been corrected in the Revised Version. The custom of filtering wine for this purpose was common among the Jews. It was founded on Lev. 11:23. It is supposed that the "lice," Ex. 8:16 (marg. R.V., "sand-flies"), were a species of gnat.

Gnat - (Webster's 1828 Dictionary)

GNAT, n. nat. A small insect, or rather a genus of insects, the Culex, whose long cylindric body is composed of eight rings. They have six legs and their mouth is formed by a flexible sheath, inclosing bristles pointed like stings. The sting is a tube containing five or six spicula of exquisite fineness, dentated or edged. The most troublesome of this genus is the musketoe.

1. Any thing proverbially small.

Ye blind guides, who strain at a gnat, and swallow a camel. Mat 23.