Rob Roy vs Robert MacGregor

Rob Roy and Robert MacGregor both are nouns.

Word	Noun	Adjective	Verb	Adverb
Rob Roy	Yes	No	No	No
Robert MacGregor	Yes	No	No	No

As nouns, Rob Roy and Robert MacGregor are synonyms defined as:

Rob Roy and Robert MacGregor: Scottish clan leader and outlaw who was the subject of a 1817 novel by Sir Walter Scott (1671-1734)

Other synonyms of Rob Roy include MacGregor, Rob Roy MacGregor.

Rob Roy (noun)	Robert MacGregor (noun)
a manhattan cocktail made with Scotch whiskey	Scottish clan leader and outlaw who was the subject of a 1817 novel by Sir Walter Scott (1671-1734)
Scottish clan leader and outlaw who was the subject of a 1817 novel by Sir Walter Scott (1671-1734)