1. 
   USL
   Upstage left.
   Found op http://www.encyclo.co.uk/local/21207
   
   
2. 
   USL
   1. Query language, close to natural English. 2. User System Language. Bellcore, 'Operations Technology Generic Requirements: User System Interface', TR-825. 3. Unix System Laboratories: the software subsidiary of AT&T, responsible for Unix System V and related software.
   Found op http://foldoc.org/USL
   
   
3. 
   USL
   Upstage left.
   Found op http://www.britishtheatreguide.info/otherresources/glossary/glosswz.htm
   
   
4. 
   usl
   1) Southeastern conf. team 2) Upstage left
   Found op http://www.mijnwoordenboek.nl/EN/crossword-dictionary/usl/1
   
   

Tip: double click on a word to show its meaning.