Mount Olympus vs Olympus

Mount Olympus and Olympus both are nouns.

Word	Noun	Adjective	Verb	Adverb
Mount Olympus	Yes	No	No	No
Olympus	Yes	No	No	No

As nouns, Mount Olympus and Olympus are synonyms defined as:

Mount Olympus and Olympus: a mountain peak in northeast Greece near the Aegean coast; believed by ancient Greeks to be the dwelling place of the gods (9,570 feet high)

Other synonyms of Mount Olympus include Mt. Olympus, Olimbos.

Mount Olympus (noun)	Olympus (noun)
a mountain peak in northeast Greece near the Aegean coast; believed by ancient Greeks to be the dwelling place of the gods (9,570 feet high)	a mountain peak in northeast Greece near the Aegean coast; believed by ancient Greeks to be the dwelling place of the gods (9,570 feet high)