How do you say dirty in Japanese?
— 汚い (きたない, kitanai)

Generic synonyms for dirty in Japanese
change変化 (へんか, henka); 変更 (へんこう, henkō)
Specialized synonyms for dirty in Japanese
mud泥 (どろ, doro)
Similar to for dirty in Japanese
black黒 (くろ, kuro)
blue青 (あお, ao)
Antonyms for dirty in Japanese
clean綺麗な (きれいな, kirei-na); 清潔 (せいけつな, seiketsu-na)