Western Isles vs Hebrides

Western Isles and Hebrides both are nouns.

Word	Noun	Adjective	Verb	Adverb
Western Isles	Yes	No	No	No
Hebrides	Yes	No	No	No

As nouns, Western Isles and Hebrides are synonyms defined as:

Western Isles and Hebrides: a group of more than 500 islands off the western coast of Scotland

Other synonyms of Western Isles include Hebridean Islands, Hebridean Isles, Western Islands.

Western Isles (noun)	Hebrides (noun)
a group of more than 500 islands off the western coast of Scotland	a group of more than 500 islands off the western coast of Scotland