NIFFIEST is a playable word

niffy Scrabble® Dictionary

adjective
niffier, niffiest
stinky
106 Playable Words can be made from "NIFFIEST"
   2-Letter Words (13 found)
   3-Letter Words (27 found)
   6-Letter Words (6 found)
   7-Letter Words (6 found)
   8-Letter Words (1 found)