culvert vs drain

culvert and drain both are nouns.

Word	Noun	Adjective	Verb	Adverb
culvert	Yes	No	No	No
drain	Yes	No	Yes	No

As nouns, drain is a hypernym of culvert; that is, drain is a word with a broader meaning than culvert:

Other hypernyms of culvert include drainpipe, waste pipe.

culvert (noun)	drain (noun)
a transverse and totally enclosed drain under a road or railway	emptying something accomplished by allowing liquid to run out of it
	a gradual depletion of energy or resources
	a pipe through which liquid is carried away
	tube inserted into a body cavity (as during surgery) to remove unwanted material

culvert (verb)	drain (verb)
	empty of liquid; drain the liquid from
	make weak
	deplete of resources
	flow off gradually