The best replacement for ux is ui.

The best alternatives to ux are rated as following:
★★★★★  ui
★★★  ia
★★  usability
★★  aix
★★  web design
★★  cx
★★  visual design
★★  ui design
★  ixd
★  ue
★  oqo
★  interaction design
★  u3
★  product management
  samsung q1
  service design
  et al
  solaris

Your alternative for ux is not listed? Suggest!
Speaking about ux, one probably shouldn't forget about penguin icomania.

Other search terms related to ux and their ratings are:
★★★★★ penguin icomania
★★★★ penguin iconmania
★ penguin brand
You have in mind a companion for ux and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of ux in all years. Click on graph for more.
ux
ui
ia