Bikini Atoll vs Bikini

Bikini Atoll and Bikini both are nouns.

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

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

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

Bikini Atoll (noun)	Bikini (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