drainage well vs storm drain

drainage well and storm drain both are nouns.

Word	Noun	Adjective	Verb	Adverb
drainage well	Yes	No	No	No
storm drain	Yes	No	No	No

As nouns, drainage well and storm drain are synonyms defined as:

drainage well and storm drain: a system of watercourses or drains for carrying off excess water

Other synonyms of drainage well include drain system, storm sewer, stormwater drain.

drainage well (noun)	storm drain (noun)
a system of watercourses or drains for carrying off excess water	a system of watercourses or drains for carrying off excess water