What is "slummed"

Usage examples of "slummed".

Bad ones come up too bright, and must be slummed, with blacking and grease, before you pass them on.

Terminal drunks and stim victims slummed the bars, while night shift workers took refuge in the coffee shop, along with the duty police officers.

He tells me, for instance, that Stanyon would be an easy ken to mill, and expresses his astonishment that no prig has, as yet, slummed it!

She mighta slummed, Alex, but I don’t see her getting anywhere near a burnout like Kristof.