'non-placental' originates from the prefix 'non-' meaning 'not' and 'placental' from Latin 'placenta' meaning 'flat cake,' referring to the flat, circular organ in the uterus of pregnant eutherian mammals.

'placenta' transformed from the Latin word 'placenta' and eventually became the modern English word 'placenta,' with 'non-' added to denote the absence of a placenta.

Initially, 'placenta' referred to a 'flat cake,' but over time it evolved into its current meaning of the organ in the uterus, with 'non-placental' indicating the absence of this organ.