fertility vs fecundity

fertility and fecundity both are nouns.

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

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

fertility: 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 fertility include fruitfulness.

As nouns, fertility and fecundity are synonyms defined as:

fertility and fecundity: the state of being fertile; capable of producing offspring

fertility (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 state of being fertile; capable of producing offspring	the intellectual productivity of a creative imagination
the ratio of live births in an area to the population of that area; expressed per 1000 population per year	the state of being fertile; capable of producing offspring