The best replacement for undercut is fade.

The best alternatives to undercut are rated as following:
★★★★★  fade
★★★★  mohawk
★★★★  hitler youth
★★★  pompadour
★★★  taper
★★  faux hawk
★★  uppercut
★  crew cut
  sidecut

Your alternative for undercut is not listed? Suggest!
Speaking about undercut, one probably shouldn't forget about beard.

Other search terms related to undercut and their ratings are:
★★★★★ beard
★★★★ short hair
★ box braids
You have in mind a companion for undercut and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of undercut in all years. Click on graph for more.
undercut
fade
mohawk