Jimmy Cagney vs James Cagney

Jimmy Cagney and James Cagney both are nouns.

Word	Noun	Adjective	Verb	Adverb
Jimmy Cagney	Yes	No	No	No
James Cagney	Yes	No	No	No

As nouns, Jimmy Cagney and James Cagney are synonyms defined as:

Jimmy Cagney and James Cagney: United States film actor known for his portrayals of tough characters (1899-1986)

Other synonyms of Jimmy Cagney include Cagney.

Jimmy Cagney (noun)	James Cagney (noun)
United States film actor known for his portrayals of tough characters (1899-1986)	United States film actor known for his portrayals of tough characters (1899-1986)