Billy the Kid vs William H. Bonney

Billy the Kid and William H. Bonney both are nouns.

Word	Noun	Adjective	Verb	Adverb
Billy the Kid	Yes	No	No	No
William H. Bonney	Yes	No	No	No

As nouns, Billy the Kid and William H. Bonney are synonyms defined as:

Billy the Kid and William H. Bonney: United States outlaw who was said to have killed 21 men (1859-1881)

Other synonyms of Billy the Kid include Billie the Kid, Bonney.

Billy the Kid (noun)	William H. Bonney (noun)
United States outlaw who was said to have killed 21 men (1859-1881)	United States outlaw who was said to have killed 21 men (1859-1881)