THUMBING is a playable word

thumb Scrabble® Dictionary

verb
thumbed, thumbing, thumbs
to leaf through with the thumb (the short, thick digit of the human hand)
83 Playable Words can be made from "THUMBING"
   2-Letter Words (14 found)
   4-Letter Words (17 found)
   5-Letter Words (5 found)
   6-Letter Words (3 found)
   8-Letter Words (1 found)