slummer's cap Share definition Flag A flat cap (usually a working-class article of clothing) when worn by someone well-off. My usual outfit for a black-tie dinner is a suit and tie with a slummer's cap for a little flair. slummer's cap by excaliburification February 27, 2011 0 0 Get merch Get the slummer's cap mug. Buy Now — $32.95 See more merch
