fatty acids and skeletally related compounds. The spelling icosanoids is preferred over the spelling eicosanoids for consistency with icosanoic acid. Specialists working in this field commonly use eicosanoids, however.
See: leukotrienes, prostanoids
PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1342 (https://doi.org/10.1351/pac199567081307)