noun, noun or participle which takes 'suru', intransitive verb
derailment; going off the rails
Literal use for trains, trams, etc. coming off the track. Also used figuratively for plans or situations going awry.
大雨の影響で電車が脱線した。
The train derailed due to heavy rain.
計画が途中で脱線してしまっ
The plan went off the rails midway.
noun, noun or participle which takes 'suru', intransitive verb
digression; going off topic
Used when a conversation, discussion, or thought strays from the main subject.
話が脱線して、会議が長引いた。
The discussion went off topic and the meeting dragged on.