gestation period vs gestation

gestation period and gestation both are nouns.

Word	Noun	Adjective	Verb	Adverb
gestation period	Yes	No	No	No
gestation	Yes	No	No	No

As nouns, gestation period and gestation are synonyms defined as:

gestation period and gestation: the period during which an embryo develops (about 266 days in humans)

gestation period (noun)	gestation (noun)
the period during which an embryo develops (about 266 days in humans)	the conception and development of an idea or plan
	the state of being pregnant; the period from conception to birth when a woman carries a developing fetus in her uterus
	the period during which an embryo develops (about 266 days in humans)