second banana
noun🔊/ˌsekənd bəˈnɑːnə/
🔊/ˌsekənd bəˈnænə/
[usually singular] (North American English, informal)an assistant, or a person who has a less important job or position than somebody else He was tired of always playing second banana. 他厌倦了总是打第二根香蕉。 The repairman left his second banana behind. 修理工把第二根香蕉留在了后面。