不潔|ふけつfuketsu[0]heiban (flat)

1. na-adjective, noununclean; dirty; unsanitary; filthy
   レストランの不潔ふけつな皿さらに私達わたしたちは吐き気はきけを催もよおさせられた。↗

   The dirty plates in the restaurant disgusted us.
2. na-adjective, nounindecent; dirty (story, money, etc.); obscene; immoral

• Synonym汚いきたないNeutralThe everyday, most common word for dirty; also mean or underhand and messy handwriting. 「不潔」 is more formal and focuses on unsanitariness.
• Synonym不衛生ふえいせいWrittenA noun for poor sanitary conditions, as in 「不衛生な環境」; typical of hygiene-management language, with a written/formal feel.
• SynonymダーティーNeutralA loanword for dirty or underhand, as in 「ダーティーな手口」; leans abstract — shady conduct and tactics rather than physical filth.
• Related薄汚いうすぎたないNeutralLooks somewhat dirty and drab, as in 「薄汚い服」; a judgement of appearance, while 「不潔」 stresses unsanitariness.
• Related汚らわしいけがらわしいWrittenWritten/formal: dirty to the point you would rather not touch it; also covers moral filth and obscenity.
• Related汚らしいきたならしいNeutralLooks filthy at a glance and puts you off; focuses on the impression the appearance gives.
• Related醜穢しゅうわいWrittenWritten/formal: ugly and filthy; rare in modern usage — say 「汚い」 in everyday speech.
• Relatedむさ苦しいむさくるしいNeutralMessy, scruffy rooms or appearance, as in 「むさ苦しい所ですが」; often a self-deprecating remark.
• Antonym清潔せいけつNeutralThe direct antonym: clean, hygienic and tidy.
• Antonym清浄せいじょうWrittenWritten/formal: pure and free of contamination, as in 「空気清浄機」; stands opposite to filth.

Use 「不潔」 for things that are unsanitary, unclean or morally improper, as in 「不潔な手」. Everyday dirt is 「汚い」; poor hygiene 「不衛生」; a shabby, scruffy look 「むさ苦しい」; dirt that disgusts 「汚らわしい」. The opposite is 「清潔」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 清きよらかでないこと。汚きたないこと。またそのさま。
2. みだらでけがらわしいさま。不道徳ふどうとくなこと。