Green’s Dictionary of Slang

north and south, the n.

a quick visual inspection, a look up and down.

[US]T.A. Dorgan in Zwilling TAD Lex. (1993) 60: Get out the old slippers, clean off the cheaters and give these the North and South.
[US]S. Lewis Babbitt (1974) 229: I know how to hop those birds! I just give um the north and south and ask um, ‘Say, who do you think you’re talking to?’.