Great Bear vs Ursa Major

Great Bear and Ursa Major both are nouns.

Word	Noun	Adjective	Verb	Adverb
Great Bear	Yes	No	No	No
Ursa Major	Yes	No	No	No

As nouns, Great Bear and Ursa Major are synonyms defined as:

Great Bear and Ursa Major: a constellation outside the zodiac that rotates around the North Star, also known as the Great Bear or Charles' Wain

Great Bear (noun)	Ursa Major (noun)
a constellation outside the zodiac that rotates around the North Star, also known as the Great Bear or Charles' Wain	a constellation outside the zodiac that rotates around the North Star, also known as the Great Bear or Charles' Wain