Americus Vespucius vs Amerigo Vespucci

Americus Vespucius and Amerigo Vespucci both are nouns.

Word	Noun	Adjective	Verb	Adverb
Americus Vespucius	Yes	No	No	No
Amerigo Vespucci	Yes	No	No	No

As nouns, Americus Vespucius and Amerigo Vespucci are synonyms defined as:

Americus Vespucius and Amerigo Vespucci: Florentine navigator who explored the coast of South America; America was named in his honor (1454-1512)

Other synonyms of Americus Vespucius include Vespucci.

Americus Vespucius (noun)	Amerigo Vespucci (noun)
Florentine navigator who explored the coast of South America; America was named in his honor (1454-1512)	Florentine navigator who explored the coast of South America; America was named in his honor (1454-1512)