QUARTO is a playable word

quarto Scrabble® Dictionary

noun
pl. quartos
the size of a piece of paper cut four from a sheet
35 Playable Words can be made from "QUARTO"
   2-Letter Words (6 found)
   3-Letter Words (18 found)
   4-Letter Words (8 found)
   5-Letter Words (2 found)
   6-Letter Words (1 found)