UNDERRUN is a playable word

underrun Scrabble® Dictionary

verb
underran, underrunning, underruns
to pass or extend under
41 Playable Words can be made from "UNDERRUN"
   2-Letter Words (8 found)
   3-Letter Words (12 found)
   4-Letter Words (13 found)
   5-Letter Words (5 found)
   6-Letter Words (2 found)
   8-Letter Words (1 found)