The best replacement for trousers is pants.

The best alternatives to trousers are rated as following:
★★★★★  pants
★★★  slacks
★★  jeans
★★  trouser
★  skirt
★  chinos
  salopettes
  5.11 tdu pants
  khakis
  skirts

Your alternative for trousers is not listed? Suggest!
Speaking about trousers, one probably shouldn't forget about braces buttons.

Other search terms related to trousers and their ratings are:
★★★★★ braces buttons
You have in mind a companion for trousers and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of trousers in all years. Click on graph for more.
trousers
pants
slacks