First and foremost, if by any chance you happen to know Bruce Springsteen, please share this post with him.
Down to business: the word ‘Boss’ is a transformation of the Hebrew idiom ‘Ba’al Habayit’, meaning master of house or business owner. In Yiddish – an Ashkenazi Jewish language – it was pronounced ‘Ba’al Habojes’ and later just ‘Balboos’.
400 years ago, following an immigration wave of jews to the Netherlands the terms assimilated into dutch as ‘bolleboos’, and became synonymous with master or intelligent person. Later, dutch immigrants to the new continent Americanized ‘bolleboos’ to ‘Boss’.
So yes, ‘Boss’ is definitely a word in English, but nonetheless a Jewish-Dutch immigrant 🙂