For questions related to lipids including but not limited to fats and their derivatives in regards to chemistry.
Per IUPAC Goldbook: Lipid 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.