ul = unlucky taken from MMORPG's usually with the ability to kill other players. Will be said by the killer.

Ul stands for upload, as aposed to DL for download.

Originates from way back in the BBS years, when giving something back for ratio on said said server.

Acronym for Uncontrollable laughter.
Created by stonemansrs.

Ultra-Left

Underwriters Laboratories, Inc. You see their logo all over the house (assuming you live in America and have electricity). They help you make sure you choose safe electric-powered stuff.

Net abbreviation for "U Loser".

See also FU

Abbreviation for Unrequited Love