Definition of placenta
plural placentas
or placentae
play
\plə-ˈsen-(ˌ)tē\
1
: the vascular organ in mammals except monotremes and marsupials that unites the fetus to the maternal uterus and mediates its metabolic exchanges through a more or less intimate association of uterine mucosal with chorionic and usually allantoic tissues;
also
: an analogous organ in another animal
2
: a sporangium-bearing surface;
especially
: the part of the carpel bearing ovules
