lipid 'Lipids' is a loosely defined term for substances of biological origin that are soluble in nonpolar solvents. They consist of saponifiable lipids, such as glycerides (fats and oils) and phospholipids, as well as nonsaponifiable lipids, principally steroids. CHEBI:14517 CHEBI:18059 CHEBI:6486 CHEBI:25054 KEGG:C01356 lipids Lipid organic molecular entity