Tonga vs Tonga language

Tonga and Tonga language both are nouns.

Word	Noun	Adjective	Verb	Adverb
Tonga	Yes	No	No	No
Tonga language	Yes	No	No	No

As nouns, Tonga and Tonga language are synonyms defined as:

Tonga and Tonga language: the language of the Tongan people of south central Africa (Zambia and Rhodesia)

Tonga (noun)	Tonga language (noun)
the language of the Tongan people of south central Africa (Zambia and Rhodesia)	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