Greek capital vs Athinai

Greek capital and Athinai both are nouns.

Word	Noun	Adjective	Verb	Adverb
Greek capital	Yes	No	No	No
Athinai	Yes	No	No	No

As nouns, Greek capital and Athinai are synonyms defined as:

Greek capital and Athinai: the capital and largest city of Greece; named after Athena (its patron goddess)

Other synonyms of Greek capital include Athens, capital of Greece.

Greek capital (noun)	Athinai (noun)
the capital and largest city of Greece; named after Athena (its patron goddess)	the capital and largest city of Greece; named after Athena (its patron goddess)