Himalaya Mountains vs Himalayas

Himalaya Mountains and Himalayas both are nouns.

Word	Noun	Adjective	Verb	Adverb
Himalaya Mountains	Yes	No	No	No
Himalayas	Yes	No	No	No

As nouns, Himalaya Mountains and Himalayas are synonyms defined as:

Himalaya Mountains and Himalayas: a mountain range extending 1500 miles on the border between India and Tibet; this range contains the world's highest mountain

Other synonyms of Himalaya Mountains include Himalaya.

Himalaya Mountains (noun)	Himalayas (noun)
a mountain range extending 1500 miles on the border between India and Tibet; this range contains the world's highest mountain	a mountain range extending 1500 miles on the border between India and Tibet; this range contains the world's highest mountain