lumbus vs loin

lumbus and loin both are nouns.

Word	Noun	Adjective	Verb	Adverb
lumbus	Yes	No	No	No
loin	Yes	No	No	No

As nouns, lumbus and loin are synonyms defined as:

lumbus and loin: either side of the backbone between the hipbone and the ribs in humans as well as quadrupeds

lumbus (noun)	loin (noun)
either side of the backbone between the hipbone and the ribs in humans as well as quadrupeds	either side of the backbone between the hipbone and the ribs in humans as well as quadrupeds
	a cut of meat taken from the side and back of an animal between the ribs and the rump