くさる・腐るkusaru[2]nakadaka (mid-high)

1. godan verb, intransitive verbto rot; to go bad; to decay; to spoil; to fester; to decompose; to turn sour (e.g. milk)
   これらのオレンジは腐くさっている。↗

   These oranges have gone bad.
2. godan verb, intransitive verbto corrode; to weather; to crumble
3. godan verb, intransitive verbto become useless; to blunt; to weaken (from lack of practice)
4. godan verb, intransitive verbto become depraved; to be degenerate; to be morally bankrupt; to be corrupt
5. godan verb, intransitive verbto be depressed; to be dispirited; to feel discouraged; to feel down
6. auxiliary verb, godan verbto have the audacity to; to be bastard enough toafter the -masu stem of a verb; indicates scorn or disdain for another's action
7. godan verb, intransitive verbto lose a bet
8. godan verb, intransitive verbto be drenched; to become sopping wet

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

• Synonym腐敗ふはいWrittenA noun for rotting or decomposition, also used figuratively for corruption as in 「政治腐敗」; more written in tone, while 「腐る」 is the everyday verb.
• SynonymすえるWrittenA written word for food going bad or turning sour; in everyday speech 「腐る」 or 「酸っぱくなる」 is used instead.
• Antonym新鮮しんせんNeutralThe antonym of 「腐る」 in terms of freshness; it describes things as fresh.

For food rotting or going bad, everyday speech uses 「腐る」, which can also describe a person becoming dispirited. Use the noun 「腐敗」 for decay or political corruption, and the written 「饐える」 for food turning sour. The antonym is 「新鮮」.

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

1. 食べ物たべものが変質へんしつし、食たべられない状態じょうたいになる。
2. 動植物どうしょくぶつの組織そしきが細菌さいきんの作用さようで分解ぶんかいし、機能きのうを失うしなう。
3. 木きや金属きんぞくがぼろぼろになる。
4. 精神せいしんなどが堕落だらくする。
5. 気分きぶんがめいる。気きが沈しずむ。すねる。
6. （動詞どうしの連用形れんようけいに付ついて）動作どうさを軽蔑けいべつする意いを表あらわす。