to flake out ------ 爽约，失职（俚语）

英文释义

(SLANG) To fail to keep an appointment, or to fulfill a duty or promise.

例句

My brother promised to play golf with me yesterday, but he flaked out, and so I played alone.

我兄弟昨天答应陪我打高尔夫球，但是他爽约了，所以我只好一个人去打。