UOENO is a corruption of the phrase "You don't even know". Colloquial vernacular predominately used in the south eastern and central southern portions of the United States. It is an expression of someones' lack of knowledge about a certain situation, circumstance, person, or matter. Can also refer to the degree that someone lacks knowledge concerning a situation, circumstance, person, or matter.
My boss made me so mad to that I was ready to quit. UOENO!

also

I heard that Tami was hitting on you. (reply) UOENO
by Urban Etymologist for Hire April 20, 2013
Get the mug
Get a uoeno mug for your guy Sarah.
The author, MS3MY, above is the most correct in that there is not a direct correlation between this acronym/abbreviation and its pronounciation.

"Yaint even know" is what these letters sound like when spat in sequence; however, all of the definitions above are also correct.
Controversy on "UOENO":

Rick Ross: Put molly up in her champagne, she aint even know it
Rick Ross: Then I took her home and I enjoyed that, she aint even know it
by Seatthell February 03, 2016
Get the merch
Get the UOENO neck gaiter and mug.
"This a thousand dollar pair of shoes and UOENO it
This a thousand dollar cup of lean and UOENO it"
by Aine Treblig August 20, 2013
Get the mug
Get a UOENO mug for your bunkmate Riley.