gnat's ass 

Very small measurement used by toolmakers & engineers, or roughly .0001 or one ten thousandth of an inch. Actual size may vary between shops, but always much less than a pussy hair. About one tenth of a skosh which is equal to approximately one nudge of the dial.

Note: When specified, generally regarded as smaller than the smallest one can measure or produce, since while most people intuitively understand that a gnat's ass is pretty small, few have actually bothered a gnat to measure one.

"Clearance is clearance, Clarance, but that die is only missing by a gnat's ass".

gnat's ass by aethernet September 4, 2006

gnat's ass 

A very small amount

Guy 1: Did you see the newbie at the party? I couldn't get near her all night.

Guy 2: Oh, yeah I saw her. I worked the floor for two hours and I was a gnat's ass away from her when she left with her friend.

gnat's ass by italknerdy October 27, 2011

Slick as a Gnat's Ass 

An unusually suave female possessed of a kind of amiable alacrity.

Well, ain't she slick as a gnat's ass!!!

Slick as a Gnat's Ass by Aziz Ibrahim November 24, 2009

gnats ass 

perfect, exact, right on the money

Jon measured the wall and told me it was gnats ass!

gnats ass by Genofam January 20, 2009