delve vs tunnel

delve is not a noun while tunnel is a noun.

Word	Noun	Adjective	Verb	Adverb
delve	No	No	Yes	No
tunnel	Yes	No	Yes	No

As verbs, tunnel is a hyponym of delve; that is, tunnel is a word with a more specific, narrower meaning than delve:

Other hyponyms of delve include furrow, groove, rut, root, rootle, rout, spade, shovel, trowel, burrow.

delve (noun)	tunnel (noun)
	a passageway through or under something, usually underground (especially one for trains or cars)
	a hole made by an animal, usually for shelter

delve (verb)	tunnel (verb)
turn up, loosen, or remove earth	force a way through
	move through by or as by digging