proton vs nucleon

proton and nucleon both are nouns.

Word	Noun	Adjective	Verb	Adverb
proton	Yes	No	No	No
nucleon	Yes	No	No	No

As nouns, nucleon is a hypernym of proton; that is, nucleon is a word with a broader meaning than proton:

proton: a stable particle with positive charge equal to the negative charge of an electron
nucleon: a constituent (proton or neutron) of an atomic nucleus

proton (noun)	nucleon (noun)
a stable particle with positive charge equal to the negative charge of an electron	a constituent (proton or neutron) of an atomic nucleus