chopper (n.)youdaoicibaDictYouDict[chopper 词源字典]
1550s, "one who chops," agent noun from chop (v.1). Meaning "meat cleaver" is by 1818. Meaning "helicopter" is from 1951, Korean War military slang (compare egg-beater); as a type of stripped-down motorcycle (originally prefered by Hells Angels) from 1965.[chopper etymology, chopper origin, 英语词源]