Green’s Dictionary of Slang

foundry n.

1. [late 19C] a shop, esp. a pork butcher’s shop because of the noise of the sausage machine.

2. [1900s] (US) a restaurant.

3. see booze foundry under booze n., doughnut foundry under doughnut n.1 , hash factory under hash n.1 , nut foundry under nut n.2 and shicker-foundry under shicker n.