Changan vs Singan

Changan and Singan both are nouns.

Word	Noun	Adjective	Verb	Adverb
Changan	Yes	No	No	No
Singan	Yes	No	No	No

As nouns, Changan and Singan are synonyms defined as:

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

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

Changan (noun)	Singan (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