LESSEN is a playable word

lessen Scrabble® Dictionary

verb
lessened, lessening, lessens
to make or become less
35 Playable Words can be made from "LESSEN"
   2-Letter Words (4 found)
   3-Letter Words (9 found)
   4-Letter Words (14 found)
   5-Letter Words (6 found)
   6-Letter Words (2 found)