developmental organism fetus http://id.loc.gov/authorities/subjects/sh85047965 http://purl.bioontology.org/ontology/MESH/D005333 http://purl.obolibrary.org/obo/NCIT_C13235 http://purl.org/sig/ont/fma/fma63919 https://en.wikipedia.org/wiki/Fetus https://www.wikidata.org/wiki/Q26513 RG600 Developmental organism from 8 weeks of gestation to birth. The unborn young of a viviparous mammal, in the postembryonic period, after the major structures have been outlined. In humans, the unborn young from the end of the eighth week after conception until birth, as distinguished from the earlier embryo, mammalian. feti fetuses foeti foetus foetuses unborn child