sicko (n.)youdaoicibaDictYouDict[sicko 词源字典]
1977, from sick (adj.) in the mental sense + ending as in weirdo. Sickie "a pervert" is attested from 1972; sicknik (1959) "pervert, obscene comedian" (applied to Lenny Bruce) has fad ending -nik.[sicko etymology, sicko origin, 英语词源]