dumpcart vs tumbril

dumpcart and tumbril both are nouns.

Word	Noun	Adjective	Verb	Adverb
dumpcart	Yes	No	No	No
tumbril	Yes	No	No	No

As nouns, tumbril is a hyponym of dumpcart; that is, tumbril is a word with a more specific, narrower meaning than dumpcart:

dumpcart: a cart that can be tilted to empty contents without handling
tumbril: a farm dumpcart for carrying dung; carts of this type were used to carry prisoners to the guillotine during the French Revolution

Other hyponyms of dumpcart include tumbrel.

dumpcart (noun)	tumbril (noun)
a cart that can be tilted to empty contents without handling	a farm dumpcart for carrying dung; carts of this type were used to carry prisoners to the guillotine during the French Revolution