/ ˈbiːtnɪk; NAmE / noun
a young person in the 1950s and early 1960s who rejected the way of life of ordinary society and showed this by behaving and dressing in a different way from most people
••
WORD ORIGIN
1950s: from beat + -nik on the pattern of sputnik , perhaps influenced by US use of Yiddish -nik , denoting someone or something who acts in a particular way.