The best replacement for mountain is hill.

The best alternatives to mountain are rated as following:
★★★★★  hill
★★★  road bike
★★★  eastern time
★★★  central time
★★★  pacific time
★  beach
★  snow summit
★  hybrid bike
★  central time zone
★  volcano
  molehill
  mountains
  red viper
  eastern time zone
  cruiser bike
  hound
  highest mountain
  hill difference
  valley
  sugar mountain
  hybrid
  windham
  freeride
  freestyle
  trail bikes
  oberyn
  traeger
  cross country
  calm clearing
  breckenridge
  eastern standard time
  road shoes
  hunter mountain
  girondins
  road bikes
  girondists
  xc
  pacific standard time
  central standard time
  camelback
  sugar
  universal studios
  winter park
  crash
  xc bikes
  hills
  wild peak
  pacific time zone
  keystone
  disneyland
  schuylkill haven
  bmx
  big sky
  lord of the rings

Your alternative for mountain is not listed? Suggest!
Speaking about mountain, one probably shouldn't forget about tea house on top.

Other search terms related to mountain and their ratings are:
★★★★★ tea house on top
★★ my hands wide open
★★ cersei
You have in mind a companion for mountain and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of mountain in all years. Click on graph for more.
mountain
hill
road bike