pack animal vs sumpter

pack animal and sumpter both are nouns.

Word	Noun	Adjective	Verb	Adverb
pack animal	Yes	No	No	No
sumpter	Yes	No	No	No

As nouns, pack animal and sumpter are synonyms defined as:

pack animal and sumpter: an animal (such as a mule or burro or horse) used to carry loads

pack animal (noun)	sumpter (noun)
an animal (such as a mule or burro or horse) used to carry loads	an animal (such as a mule or burro or horse) used to carry loads