Green’s Dictionary of Slang

lit. credibility; the term, as used mainly in the 1970s–80s by young people (and those who purvey their material wants), was used to indicate that something had a populist, anti-establishment, ‘street’ level of acceptability.

1986		(ref. to 1970s) B. Geldof Is That It? 125: ‘Cred’ was achieved by your rhetorical stance and no one had more credibility than the Clash.
1996		A. Close Official and Doubtful 87: He’s dressed in a faded and rumpled denim shirt and a darker shade of jeans. Poly lecturer cred.
2000		T. Fontana ‘Bill of Wrongs’ Oz ser. 4 ep. 3 [TV script] We don’t want a partner who is loco. You come with cred.
2004		Guardian G2 4 Mar. 18: Sid lost all his jail cred for saving Morris.
2012		L. Jose ‘Underhooks’ in Crime Factory: Hard Labour [ebook] He’d started with the crowd on his side, his old cred buying him the benefit of the doubt.
2015		P. Beatty Sellout (2016) 183: Panache wasn’t no punk, but Stevie gave him real street cred in the rap scene.
2021		P. Papathanasiou Stoning 211: Their colourful pasts [...] earned them street cred and sold millions of albums.
2022		J. Hannaham Didn’t Nobody Give a Shit 23: Her lawyer had coached her to [...] boost her cred.