placentation vs activity

placentation and activity both are nouns.

Word	Noun	Adjective	Verb	Adverb
placentation	Yes	No	No	No
activity	Yes	No	No	No

As nouns, activity is a hypernym of placentation; that is, activity is a word with a broader meaning than placentation:

Other hypernyms of placentation include bodily function, bodily process, body process.

placentation (noun)	activity (noun)
arrangement of the ovules in the placenta and of the placentas in the ovary	any specific behavior
the formation of the placenta in the uterus	the trait of being active; moving or acting rapidly and energetically
	an organic process that takes place in the body
	a process existing in or produced by nature (rather than by the intent of human beings)
	the state of being active
	(chemistry) the capacity of a substance to take part in a chemical reaction