SOLO is a playable word

solo Scrabble® Dictionary

noun
pl. solos or soli
a musical composition for a single voice or instrument
verb
soloed, soloing, solos or soloes
to perform alone
7 Playable Words can be made from "SOLO"
   2-Letter Words (3 found)
   3-Letter Words (2 found)
   4-Letter Words (2 found)