cart vs underrun

cart is a noun but underrun is not a noun.

Word	Noun	Adjective	Verb	Adverb
cart	Yes	No	Yes	No
underrun	No	No	Yes	No

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

Other hyponyms of cart include bouse, bowse.

cart (noun)	underrun (noun)
a heavy open wagon usually having two wheels and drawn by an animal
wheeled vehicle that can be pushed by a person; may have one or two or four wheels

cart (verb)	underrun (verb)
draw slowly or heavily	haul onto a boat
transport something in a cart	run or pass below