1The tip, edge, or outer boundary of something — e.g., the edge of a table, road, or object.
机の端に本を置かないでください。落ちますよ。
Please don't put the book on the edge of the desk. It'll fall.
この道の端を歩けば、車に轢かれる心配はありません。
If you walk along the edge of this road, there's no risk of being hit by a car.
紙の端を少し折って目印にした。
I folded a corner of the paper slightly as a marker.
崖の端に立つと足がすくむ。
My legs freeze up when I stand at the edge of a cliff.
2The starting point or trigger of something; commonly used in the phrase 〜に端を発する ("originating from ~").
二人の喧嘩は些細な誤解に端を発している。
The fight between the two of them originated from a trivial misunderstanding.
そのブームは一つのSNS投稿に端を発した。
That boom originated from a single social media post.
3A leftover scrap or fragment; also used to mean something trivial or barely worth considering.
工作で余った木の端は捨てずに取っておいた。
I kept the leftover scraps of wood from the craft project instead of throwing them away.
彼の意見なんて端にもかけていない。
I don't give his opinion a second thought.