burrow vs tunnel

burrow and tunnel both are nouns.

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

As nouns, burrow and tunnel are synonyms defined as:

As verbs, burrow and tunnel are synonyms defined as:

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

burrow (verb)	tunnel (verb)
move through by or as by digging	force a way through
	move through by or as by digging