Green’s Dictionary of Slang

(W.I./UK black/US gay) to strike an exaggerated pose.

1950		Bennett, Clarke & Wilson Anancy Stories and Dialect Verse 16: Nancy se one big picture a Puss pose off eena de book.
1973		C. Gaines Stay Hungry 28: He’s posin, man. That’s some of the greatest posin you ever saw.
1976		J. Hayes ‘Gayspeak’ Quarterly Journal Speech LXI 256–66: In his white levis and jacket just posing up a storm.
1997		C. Newland Scholar 211: I’d make a fine one wouldn’t I? Dissin’ you for doin’ the armed, yet posin’ off with my earings an’ necklaces an’ all dat.
2001		(con. 1981) A. Wheatle East of Acre Lane 63: He don’t buy much tune but he poses off his jewellery at the counter, innit.