trespasser vs unwelcome person

trespasser and unwelcome person both are nouns.

Word	Noun	Adjective	Verb	Adverb
trespasser	Yes	No	No	No
unwelcome person	Yes	No	No	No

As nouns, unwelcome person is a hypernym of trespasser; that is, unwelcome person is a word with a broader meaning than trespasser:

trespasser: someone who intrudes on the privacy or property of another without permission
unwelcome person: a person who for some reason is not wanted or welcome

Other hypernyms of trespasser include persona non grata, entrant.

trespasser (noun)	unwelcome person (noun)
someone who intrudes on the privacy or property of another without permission	a person who for some reason is not wanted or welcome