one matter; one item; one case
Used to count or refer to a single matter, item, or case, often in formal, business, or news contexts. Functions as a noun with a built-in counter meaning.
A fee of 500 yen is charged per case.
This matter has not been resolved yet.
I apologize for the incident the other day.
The police are investigating the fraud case.
案件 refers to a matter or agenda item, often in business or legal contexts, while 一件 emphasizes treating it as a single, countable instance.
一件 is the everyday word for one matter or case, while 一条 sounds more literary or formal and is typical of news reports and official writing.
事件 means an incident or affair in a general sense, while 一件 specifically refers to a single matter or case being counted or referred to.
一軒 (いっけん) counts houses or buildings, while 一件 (いっけん) counts cases, matters, or incidents; they sound identical but refer to completely different things.
Compound of 一 (one) and 件 (matter, item, case). The reading いっけん follows regular sound changes for 一 before a k-row kanji.