prolificacy vs fecundity

prolificacy and fecundity both are nouns.

Word	Noun	Adjective	Verb	Adverb
prolificacy	Yes	No	No	No
fecundity	Yes	No	No	No

As nouns, fecundity is a hypernym of prolificacy; that is, fecundity is a word with a broader meaning than prolificacy:

prolificacy: the property of producing abundantly and sustaining vigorous and luxuriant growth
fecundity: the quality of something that causes or assists healthy growth

Other hypernyms of prolificacy include fruitfulness.

prolificacy (noun)	fecundity (noun)
the property of producing abundantly and sustaining vigorous and luxuriant growth	the quality of something that causes or assists healthy growth
	the intellectual productivity of a creative imagination
	the state of being fertile; capable of producing offspring