fat - a soft greasy substance occurring in organic tissue and consisting of a mixture of lipids (mostly triglycerides); "pizza has too much fat"

acylglycerol, glyceride - an ester of glycerol and fatty acids that occurs naturally as fats and fatty oils; "fresh fats contain glycerides of fatty acids and very little free acid"

lipid, lipide, lipoid - an oily organic compound insoluble in water but soluble in organic solvents; essential structural component of living cells (along with proteins and carbohydrates)