COSMOS is a playable word

cosmos Scrabble® Dictionary

noun
pl. cosmoses
the universe regarded as an orderly system
22 Playable Words can be made from "COSMOS"
   2-Letter Words (4 found)
   3-Letter Words (9 found)
   4-Letter Words (6 found)
   5-Letter Words (2 found)
   6-Letter Words (1 found)