TUNNELLING is a playable word

tunnel Scrabble® Dictionary

verb
tunneled, tunneling, tunnels or tunnelled, tunnelling, tunnels
to dig a tunnel (an underground passageway)
148 Playable Words can be made from "TUNNELLING"
   2-Letter Words (13 found)
   7-Letter Words (6 found)
   8-Letter Words (2 found)
   9-Letter Words (1 found)
   10-Letter Words (1 found)