donkey cart vs pony cart

donkey cart and pony cart both are nouns.

Word	Noun	Adjective	Verb	Adverb
donkey cart	Yes	No	No	No
pony cart	Yes	No	No	No

As nouns, donkey cart and pony cart are synonyms defined as:

Other synonyms of donkey cart include ponycart, tub-cart.

donkey cart (noun)	pony cart (noun)
a cart with an underslung axle and two seats	a cart with an underslung axle and two seats