bearer vs messenger

bearer and messenger both are nouns.

Word	Noun	Adjective	Verb	Adverb
bearer	Yes	No	No	No
messenger	Yes	No	No	No

As nouns, messenger is a hypernym of bearer; that is, messenger is a word with a broader meaning than bearer:

Other hypernyms of bearer include courier.

bearer (noun)	messenger (noun)
a messenger who bears or presents	a person who carries a message
one of the mourners carrying the coffin at a funeral
the person who is in possession of a check or note or bond or document of title that is endorsed to him or to whoever holds it
someone whose employment involves carrying something