UMMING is a playable word

um Scrabble® Dictionary

verb
ummed, umming, ums
to hesitate or pause in speaking
25 Playable Words can be made from "UMMING"
   2-Letter Words (8 found)
   3-Letter Words (13 found)
   4-Letter Words (2 found)
   5-Letter Words (1 found)
   6-Letter Words (1 found)