harbour vs seaport

harbour and seaport both are nouns.

Word	Noun	Adjective	Verb	Adverb
harbour	Yes	No	Yes	No
seaport	Yes	No	No	No

As nouns, harbour and seaport are synonyms defined as:

harbour and seaport: a sheltered port where ships can take on or discharge cargo

Other synonyms of harbour include harbor, haven.

harbour (noun)	seaport (noun)
a place of refuge and comfort and security	a sheltered port where ships can take on or discharge cargo
a sheltered port where ships can take on or discharge cargo

harbour (verb)	seaport (verb)
maintain (a theory, thoughts, or feelings)
hold back a thought or feeling about
keep in one's possession; of animals
secretly shelter (as of fugitives or criminals)