Wordnet 3.0
NOUN (2)
1.
the formation of the placenta in the uterus;
2.
arrangement of the ovules in the placenta and of the placentas in the ovary;
The Collaborative International Dictionary of English v.0.48:
Placentation \Plac`en*ta"tion\, n.
1. (Anat.) The mode of formation of the placenta in different
animals; as, the placentation of mammals.
[1913 Webster]
2. (Bot.) The mode in which the placenta is arranged or
composed; as, axile placentation; parietal placentation.
[1913 Webster]
WordNet (r) 3.0 (2006):
placentation
n 1: the formation of the placenta in the uterus
2: arrangement of the ovules in the placenta and of the
placentas in the ovary