great power vs superpower

great power and superpower both are nouns.

Word	Noun	Adjective	Verb	Adverb
great power	Yes	No	No	No
superpower	Yes	No	No	No

As nouns, great power and superpower are synonyms defined as:

great power and superpower: a state powerful enough to influence events throughout the world

Other synonyms of great power include major power, power, world power.

great power (noun)	superpower (noun)
a state powerful enough to influence events throughout the world	a state powerful enough to influence events throughout the world