(1):

(n.) An amorphous, gelatinous substance containing nitrogen, found in milk and other animal fluids. It resembles peptone, and is variously regarded as a coagulating or emulsifying agent.

(2):

(n.) A white waxy substance found in the sap of the South American cow tree (Galactodendron).

(3):

(n.) An amorphous, gummy carbohydrate resembling gelose, found in the seeds of leguminous plants, and yielding on decomposition several sugars, including galactose.