Friendly Islands vs Tonga

Friendly Islands and Tonga both are nouns.

Word	Noun	Adjective	Verb	Adverb
Friendly Islands	Yes	No	No	No
Tonga	Yes	No	No	No

As nouns, Friendly Islands and Tonga are synonyms defined as:

Friendly Islands and Tonga: a monarchy on a Polynesian archipelago in the South Pacific; achieved independence from the United Kingdom in 1970

Other synonyms of Friendly Islands include Kingdom of Tonga.

Friendly Islands (noun)	Tonga (noun)
a monarchy on a Polynesian archipelago in the South Pacific; achieved independence from the United Kingdom in 1970	the language of the Tongan people of south central Africa (Zambia and Rhodesia)
	a monarchy on a Polynesian archipelago in the South Pacific; achieved independence from the United Kingdom in 1970