English

implacental

From im- + placental.

Proto-Indo-European *h₁én ‘in’

Proto-Germanic *in ‘into’

English in-

Proto-Hellenic *pləks

…

Ancient Greek πλακοῦς ‘flat cake’

Ancient Greek πλακόεντα

Latin placenta

Latin placentalis

Today it means

adj Not having a placenta (said of e.g. marsupials and monotremes).

Language periods are conventional ranges, not dates for this word.

Etymograph / implacental