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.
Source:
PAC, 1995, 67, 1307
(Glossary of class names of organic compounds and reactivity intermediates based on
structure (IUPAC Recommendations 1995))
on page 1348
See also:
White Book, p. 180