LW stands for Light Weight. Meaning it has relative relation to someone of something.

Dejagoo is the strange feeling that you've been in this sticky situation before. It is dejavu due to goo. Usual symptoms are shivers down once's spine followed by disgust, especially if actual goo is involved.

A term used by (mostly) people with eating disorders meaning lowest weight

"love weed", to be used interchangeably with any term for marijuana, but used in order to not attract attention to what you are discussing.. or to be used as a farewell at the end of a conversation between two weed addicts

Lord-willing. In other words, if the Lord is willing or if it is the Lord's will. See James 4:13-15.
This abbreviation precedes some likely but not absolutely certain prediction.

Lucky Win
In any competitive game where one wins despite percentages or inferior level of skill using luck
(mainly used in Poker)

meaning "Last Word" in an argument or after an online game has concluded.