Bangkok vs Krung Thep

Bangkok and Krung Thep both are nouns.

Word	Noun	Adjective	Verb	Adverb
Bangkok	Yes	No	No	No
Krung Thep	Yes	No	No	No

As nouns, Bangkok and Krung Thep are synonyms defined as:

Bangkok and Krung Thep: the capital and largest city and chief port of Thailand; a leading city in southeastern Asia; noted for Buddhist architecture

Other synonyms of Bangkok include capital of Thailand.

Bangkok (noun)	Krung Thep (noun)
the capital and largest city and chief port of Thailand; a leading city in southeastern Asia; noted for Buddhist architecture	the capital and largest city and chief port of Thailand; a leading city in southeastern Asia; noted for Buddhist architecture