gravidness vs pregnancy

gravidness and pregnancy both are nouns.

Word	Noun	Adjective	Verb	Adverb
gravidness	Yes	No	No	No
pregnancy	Yes	No	No	No

As nouns, pregnancy is a hypernym of gravidness; that is, pregnancy is a word with a broader meaning than gravidness:

gravidness: technical terms for pregnancy
pregnancy: the state of being pregnant; the period from conception to birth when a woman carries a developing fetus in her uterus

Other hypernyms of gravidness include gestation, maternity.

gravidness (noun)	pregnancy (noun)
technical terms for pregnancy	the state of being pregnant; the period from conception to birth when a woman carries a developing fetus in her uterus