FROSTS is a playable word

frost Scrabble® Dictionary

verb
frosted, frosting, frosts
to cover with frost (a deposit of minute ice crystals)
28 Playable Words can be made from "FROSTS"
   2-Letter Words (5 found)
   3-Letter Words (9 found)
   4-Letter Words (9 found)
   5-Letter Words (4 found)
   6-Letter Words (1 found)