cleanest

free from dirt or impurities; or having clean habits;
free of restrictions or qualifications;
(of sound or color) free from anything that dulls or dims;
free from impurities;
(of a record) having no marks of discredit or offense;
ritually clean or pure
not spreading pollution or contamination; especially radioactive contamination;
(of behavior or especially language) free from objectionable elements; fit for all observers;
free from sepsis or infection;
morally pure;
(of a manuscript) having few alterations or corrections;
(of a surface) not written or printed on;
exhibiting or calling for sportsmanship or fair play;
without difficulties or problems;
thorough and without qualification;
not carrying concealed weapons
free from clumsiness; precisely or deftly executed;
free of drugs;

cleanest is a valid Scrabble (US) TWL word

cleanest is a valid Scrabble Word in Merriam-Webster MW Dictionary

cleanest is a valid Scrabble Word in International Collins CSW Dictionary

cleanest is a valid Words With Friends word