excreta EHDAA2_RETIRED:0003184 AEO:0000184 BTO:0000491 excreted substance galen:Excretion portion of excreted substance FMA:9674 waste substance ENVO:02000022 A portion of organism substance that is the product of an excretion process that will be eliminated from the body. An excretion process is elimination by an organism of the waste products that arise as a result of metabolic activity. excretion organism substance