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

Briefly, "the realization that each random passerby is living a life as vivid and complex as your own." Originally from the Dictionary of Obscure Sorrows, which has a lot more beautiful neologism definitions like this you might enjoy.

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.

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.

Ultra-Left

Net abbreviation for "U Loser".

See also FU