Lake Onega vs Onega

Lake Onega and Onega both are nouns.

Word	Noun	Adjective	Verb	Adverb
Lake Onega	Yes	No	No	No
Onega	Yes	No	No	No

As nouns, Lake Onega and Onega are synonyms defined as:

Lake Onega and Onega: lake in northwestern Russia near the border with Finland; second largest lake in Europe

Lake Onega (noun)	Onega (noun)
lake in northwestern Russia near the border with Finland; second largest lake in Europe	lake in northwestern Russia near the border with Finland; second largest lake in Europe