cleanest
clean-est
adjective
Having the least dirt, marks, or impurities; most hygienic or pure.
"This is the cleanest room in the whole house."
Thesaurus
Synonyms: clean, uncontaminating, antiseptic, uninfected, cleanse, adroit, neat, legible, fair, unarmed, clean and jerk, moral
Antonyms: begrime, below the belt, bemire, colly, contaminating, dirty, grime, impure, soil, soiled, unclean, unfairly