What is the meaning of Glycerol?

1,2,3-trihydroxy-propane or propan-1,2,3-triol; a trihydric alcohol

A syrupy sweet liquid obtained as a by-product in the manufacture of soap from animal or vegetable oils and fats; it is used as an antifreeze, a plasticizer, and a food sweetener and in the manufacture of dynamite, cosmetics etc.

Source: wiktionary.org