call sign
英 [ˈkɔːl saɪn]
美 [ˈkɔːl saɪn]
n. (无线电通讯的)呼叫信号，呼号
牛津词典
noun
- （无线电通讯的）呼叫信号，呼号
the letters and numbers used in radio communication to identify the person who is sending a message
柯林斯词典
- (电台的)呼叫信号
Acall signis the letters and numbers which identify a person, vehicle, or organization that is broadcasting on the radio or sending messages by radio.