ei·co·sa·noid 
(īkō-sə-noid′)
(īkō-sə-noid′)n.
Any of a group of substances that are derived from arachidonic acid, including leukotrienes, prostaglandins, and thromboxanes.
[eicosan(e), chemical name (Greek eikosi, twenty, from its twenty carbon atoms; see wīktī- in the Appendix of Indo-European roots + -ANE) + -OID.]