Green’s Dictionary of Slang

khakis n.

[abbr.]

khaki shorts or clothes.

[US]UGK ‘Trill Ass Nigga’ 🎵 So watch out for the niggaz in the khakis.
[US]E. Bunker Mr Blue 349: Half a dozen guards come from the adjustment center, leading a trio of prisoners in khakis (out to court clothes).