LISP is a playable word

lisp Scrabble® Dictionary

verb
lisped, lisping, lisps
to pronounce the letters {it}s{/it} and {it}z{/it} imperfectly
12 Playable Words can be made from "LISP"
   2-Letter Words (4 found)
   3-Letter Words (5 found)
   4-Letter Words (3 found)