excreta 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 AEO:0000184 BTO:0000491 EHDAA2_RETIRED:0003184 ENVO:02000022 FMA:9674 UBERON:0000174 UBERON:0000324 UBERON:0007550 excreted substance excretion galen:Excretion portion of excreted substance uberon waste substance organism substance