Any of a family of enzymes that catalyse the hydrolysis of triglycerides into fatty acids and glycerol. Lipase secreted by the liver digests fats in the small intestine for absorption by the intestinal epithelial cells, whereas lipases in the bloodstream hydrolyse the reconstituted fats in chylomicrons for uptake by muscle cells or adipose tissue. Lipases in adipose cells hydrolyse stored triglycerides when fat is mobilized to re-enter the bloodstream as fatty acids.