FUNCTIONING is a playable word

function Scrabble® Dictionary

verb
functioned, functioning, functions
to be in action
150 Playable Words can be made from "FUNCTIONING"
   2-Letter Words (14 found)
   8-Letter Words (4 found)
   9-Letter Words (3 found)
   10-Letter Words (1 found)
   11-Letter Words (1 found)