noun
coming to nothing; falling through; being ruined
Colloquial noun meaning that a plan, effort, or thing has ended in failure or become useless. Often used in phrases like おじゃんになる.
雨でピクニックがおじゃんになった。
The picnic was ruined because of the rain.
せっかくの計画がおじゃんだ。
All our careful planning came to nothing.
The origin is uncertain. One theory suggests it comes from the sound of a bell or gong signaling the end of something, but this is not confirmed.