NIFFING is a playable word

niff Scrabble® Dictionary

verb
niffed, niffing, niffs
to stink
13 Playable Words can be made from "NIFFING"
   2-Letter Words (3 found)
   3-Letter Words (6 found)
   4-Letter Words (1 found)
   6-Letter Words (2 found)
   7-Letter Words (1 found)