beacon light vs lighthouse

beacon light and lighthouse both are nouns.

Word	Noun	Adjective	Verb	Adverb
beacon light	Yes	No	No	No
lighthouse	Yes	No	No	No

As nouns, beacon light and lighthouse are synonyms defined as:

beacon light and lighthouse: a tower with a light that gives warning of shoals to passing ships

Other synonyms of beacon light include beacon, pharos.

beacon light (noun)	lighthouse (noun)
a tower with a light that gives warning of shoals to passing ships	a tower with a light that gives warning of shoals to passing ships