Green’s Dictionary of Slang

chokka n.

also chocker
[ety. unknown]

a man.

[UK]Partridge DSUE (1984) 212/1: chocker gen. old chocker A man [...] from ca. 1860.
[UK]A. Sillitoe Birthday 201: An old chokka at the bar asked why I was looking so white in the gills.