WALLS is a playable word

wall Scrabble® Dictionary

verb
walled, walling, walls
to provide with a wall (an upright structure built to enclose an area)
19 Playable Words can be made from "WALLS"
   2-Letter Words (4 found)
   3-Letter Words (8 found)
   4-Letter Words (6 found)
   5-Letter Words (1 found)