punk

In prison slang, a male inmate coerced — by threat, debt, or actual violence — into being another inmate's sexual partner, often in return for protection, commissary, or just being left alone. The word carries heavy stigma inside; calling someone a punk is a direct challenge. Distinct from the music subculture or the general 'worthless person' sense.

More broadly, a contemptible or cowardly person. Mainstream American insult: weak, untrustworthy, beneath respect. This sense leaks out of prison/street usage into everyday speech.

An inexperienced young man, especially a small-time hoodlum or troublemaker. Older American sense, common in noir fiction and police slang from the 1920s on.