腐敗
fuhai[ɸɯ̟ha̠i]
The Japanese phrase for 'to rot' is 腐敗 (fuhai), which is the default form.
腐敗 (fuhai) can refer to biological decomposition, but it is frequently used metaphorically to describe political or social corruption. For everyday situations involving organic matter or food going bad, the verb 腐る (kusaru) is the most common and versatile way to say 'rot' in Japanese.
Meaning: (intransitive) to suffer decomposition (verb)
Which one should you use?
The verb 腐る (kusaru) is more commonly used for food or organic matter going bad in everyday speech, whereas 腐敗 (fuhai) sounds more formal, scientific or systemic.
How does it change in a sentence?
To indicate that something is currently rotting, you can use the progressive form 腐っている (kusatteiru).
How do you pronounce it?
fuhai
Did you know?
- The word 腐る (kusaru) is used in the phrase 腐っても鯛 (kusatte mo tai), meaning 'even a rotten sea bream is still a sea bream'.
- While 腐敗 (fuhai) describes systemic corruption, the verb 腐る (kusaru) can also be used as slang to mean 'to be fed up' or 'to be disgusted' with a situation.
- Japanese has a distinct word for 'fermentation', 発酵 (hakkō), which is biologically similar to rotting but is viewed as a positive, controlled process.
Examples in context
- かごの中の果物が腐ってきた。The fruit in the basket has started to rot.
- この環境では腐敗が進みやすい。kono kankyo dewa fuhai ga susumiyasui.Decomposition progresses easily in this environment.
- 腐敗の臭いが漂っている。fuhai no nioi ga tadayotte iru.The smell of decomposition is lingering.
Example conversation
Ren and Misaki are checking the refrigerator.
- 蓮 Renこの野菜、腐敗してないかな？kono yasai, fuhai shite nai kana?I wonder if these vegetables have rotted?
- 美咲 Misakiあ、少し変な匂いがするね。a, sukoshi hen na nioi ga suru ne.Oh, they smell a bit strange.
- 蓮 Renやっぱり腐敗していたみたいだ。yappari fuhai shite ita mitai da.It seems they really had rotted.
- 美咲 Misaki蓮、すぐに捨ててちょうだい。Ren, sugu ni sutete choudai.Ren, please throw them away immediately.
Sources
- Pronunciation: Wiktionary entry 腐敗, CC BY-SA 4.0, dump of 2026-09-26.
