Bikini vs Bikini Atoll

Bikini and Bikini Atoll both are nouns.

Word	Noun	Adjective	Verb	Adverb
Bikini	Yes	No	No	No
Bikini Atoll	Yes	No	No	No

As nouns, Bikini and Bikini Atoll are synonyms defined as:

Bikini and Bikini Atoll: an atoll in the Marshall Islands; formerly used by the United States as a site for testing nuclear weapons

Bikini (noun)	Bikini Atoll (noun)
an atoll in the Marshall Islands; formerly used by the United States as a site for testing nuclear weapons	an atoll in the Marshall Islands; formerly used by the United States as a site for testing nuclear weapons