Himalaya Mountains vs Himalaya

Himalaya Mountains and Himalaya both are nouns.

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

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

Himalaya Mountains and Himalaya: 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 Himalayas.

Himalaya Mountains (noun)	Himalaya (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