any of a group of natural biochemicals, as serotonin, angiotensin, or histamine, that activate changes in the blood, nerves, etc., similar to those caused by drugs
Origin:
aut(o)- + Gr akos, cure, remedy + -oid
See autacoid in American Heritage Dictionary 4
also au·to·coid
noun
An organic substance, such as a hormone, produced in one part of an organism and transported by the blood, lymph, or sap to another part of the organism where it exerts a physiologic effect on that part.