bread and butter
某人的主要收入来源
口语·形容主要收入来源
英文释义
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.
典故来源
源自16世纪欧洲，面包和黄油是日常基本食物，比喻维持生计的主要收入来源。