Zetland vs Shetland Islands

Zetland and Shetland Islands both are nouns.

Word	Noun	Adjective	Verb	Adverb
Zetland	Yes	No	No	No
Shetland Islands	Yes	No	No	No

As nouns, Zetland and Shetland Islands are synonyms defined as:

Zetland and Shetland Islands: an archipelago of about 100 islands in the North Atlantic off the north coast of Scotland

Other synonyms of Zetland include Shetland.

Zetland (noun)	Shetland Islands (noun)
an archipelago of about 100 islands in the North Atlantic off the north coast of Scotland	an archipelago of about 100 islands in the North Atlantic off the north coast of Scotland