UPSTIRS is a playable word

upstir Scrabble® Dictionary

verb
upstirred, upstirring, upstirs
to stir up
89 Playable Words can be made from "UPSTIRS"
   2-Letter Words (8 found)
   3-Letter Words (25 found)
   6-Letter Words (10 found)
   7-Letter Words (2 found)