North Star vs pole star

North Star and pole star both are nouns.

Word	Noun	Adjective	Verb	Adverb
North Star	Yes	No	No	No
pole star	Yes	No	No	No

As nouns, North Star and pole star are synonyms defined as:

North Star and pole star: the brightest star in Ursa Minor; at the end of the handle of the Little Dipper; the northern axis of the earth points toward it

Other synonyms of North Star include polar star, Polaris, polestar.

North Star (noun)	pole star (noun)
the brightest star in Ursa Minor; at the end of the handle of the Little Dipper; the northern axis of the earth points toward it	the brightest star in Ursa Minor; at the end of the handle of the Little Dipper; the northern axis of the earth points toward it