Xi'an vs Changan

Xi'an and Changan both are nouns.

Word	Noun	Adjective	Verb	Adverb
Xi'an	Yes	No	No	No
Changan	Yes	No	No	No

As nouns, Xi'an and Changan are synonyms defined as:

Xi'an and Changan: a city of central China; capital of ancient Chinese empire 221-206 BC

Other synonyms of Xi'an include Hsian, Sian, Singan, Xian.

Xi'an (noun)	Changan (noun)
a city of central China; capital of ancient Chinese empire 221-206 BC	a city of central China; capital of ancient Chinese empire 221-206 BC