FILLER is a playable word

filler Scrabble® Dictionary

noun
pl. fillers
one that fills
44 Playable Words can be made from "FILLER"
   2-Letter Words (7 found)
   3-Letter Words (13 found)
   4-Letter Words (14 found)
   5-Letter Words (8 found)
   6-Letter Words (2 found)