The story
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: A solution of proteins and other bio-nutrients obtained as a coproduct in the processing of animal by-products; typically produced at a slaughterhouse, or at rendering facilities which processes fishmeal or meat and bone meal. Stickwater is furthermore processed and added to animal feeds as a source of nutrients. Full definition →
Etymology from Wiktionary, CC BY-SA 4.0.