Green’s Dictionary of Slang

clothes n.

In compounds

clothes-bag (n.)

(US black) a well-dressed, clothes-conscious woman.

[US]A. Crummell in Hartman Wayward Lives (2019) 117: Nothing is more contemptible than the crowds of these dandaical ‘Clothes-bags’ [...] full of vanity and pretense, poisoned with lust and whiskey and too proud [...] to work.

In phrases

in clothes [abbr. SE plain clothes]

(US) working as a detective.

[US]E. Droge Patrolman 185: I decided to attend the course and spend my last few months in ‘clothes.’.
[US]J.B. Rubinstein City Police 397: Everyone assumes that plain-clothesmen take something. ‘They’ve been in clothes for some time now. You know how it is, everybody in the district knows who they are but they still make some pinches.’.

In exclamations

keep your clothes on!

(US) control yourself, calm down.

[US]J. Jackson Pineapple Street 231: ‘Jesus, keep your clothes on, George.’ Cord tried to reel his sister in.