Webster's dictionary defines punk as
1
archaic : prostitute
2
[probably partly from 3punk]
: nonsense, foolishness
3
a : a young inexperienced person : beginner, novice; especially : a young man
b : a usually petty gangster, hoodlum, or ruffian
c slang : a young man used as a homosexual partner especially in a prison
4
a : punk rock
b : a punk rock musician
c : one who affects punk styles