UNFASTENING is a playable word

unfasten Scrabble® Dictionary

verb
unfastened, unfastening, unfastens
to release from fastenings
513 Playable Words can be made from "UNFASTENING"
   2-Letter Words (27 found)
   3-Letter Words (95 found)
   9-Letter Words (2 found)
   11-Letter Words (1 found)