Newton vs Isaac Newton

Newton and Isaac Newton both are nouns.

Word	Noun	Adjective	Verb	Adverb
Newton	Yes	No	No	No
Isaac Newton	Yes	No	No	No

As nouns, Newton and Isaac Newton are synonyms defined as:

Newton and Isaac Newton: English mathematician and physicist; remembered for developing the calculus and for his law of gravitation and his three laws of motion (1642-1726)

Other synonyms of Newton include Sir Isaac Newton.

Newton (noun)	Isaac Newton (noun)
English mathematician and physicist; remembered for developing the calculus and for his law of gravitation and his three laws of motion (1642-1726)	English mathematician and physicist; remembered for developing the calculus and for his law of gravitation and his three laws of motion (1642-1726)