one line; one streak; one stripe; one ray; one wisp
Counts long, thin things: lines, streaks, stripes, rays of light, wisps of smoke, etc. Used with the counter 条.
A single ray of light shone through a break in the clouds.
There was a single scar line across his back.
one item; one clause; one passage
Counts items in a list, clauses in a document, or passages in a text. Often used in formal or legal contexts.
Please check Article 1 of the contract.
This law consists of a single clause.
one matter; one affair; one incident
Refers to a single matter, event, or case. Somewhat literary or formal; often used in news or reports.
They requested a detailed explanation regarding that one matter.
The newspaper covered the incident as a single article.
A single wisp of smoke rose into the sky.
An important condition is written in one clause of this contract.
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.
一乗 shares the exact reading いちじょう with 一条 but means 'first power' (math) or 'one vehicle' (Buddhism), so the two are unrelated in meaning despite sounding identical.