bread and butter
某人的主要收入來源
口語·形容主要收入來源
英文釋義
a person's main source of income or livelihood
例句
Teaching English is her bread and butter, so she can't afford to lose this job.
典故來源
源自16世紀(jì)歐洲,面包和黃油是日常基本食物,比喻維持生計(jì)的主要收入來源。