HARDER is a playable word

hard Scrabble® Dictionary

adjective
harder, hardest
firm and unyielding
44 Playable Words can be made from "HARDER"
   2-Letter Words (12 found)
   3-Letter Words (12 found)
   4-Letter Words (14 found)
   5-Letter Words (5 found)
   6-Letter Words (1 found)