1. LW - Noun
2. LW - Proper noun
(electronics) Initialism of long wave.
Initialism of low water.
(linguistics) Abbreviation of loanword.
Initialism of letter writer — used as short-hand in comments to 'Dear Dorothy' advice columns. If there is more than one letter, then it's LWn, where n is the first/second etc. letter, such as LW1, LW2, and so on.
Initialism of left wing.
LW
Initialism of Lawyer's Weekly, an Australian newspaper for lawyers