Green’s Dictionary of Slang

1. a city; thus its streets.

1989		A. Vachss Hard Candy (1990) 41: If you stayed on the concrete, maybe you got your name in the papers.
2000		N. Barlay Crumple Zone 177: Heading west up the A40, towards the M25, the motorway that marks the end of the concrete.

2. (Aus.) an urban individual, e.g. a businessman, who poses as a rural dweller.

1996		Newsweek 128 1-14 8/3: Concrete Cowboy: City slickers in boots and cowboy hats.
2021		Betoota-isms 65: Concrete Cowboy [...] 1. Inner-city business professional who pounds the pavement in R.M. Williams, a gingham check shirt and a puffer vest 2. A man who has never actually ridden a horse, but dresses as though he does it for work.