per centum vs percent

per centum and percent both are nouns.

Word	Noun	Adjective	Verb	Adverb
per centum	Yes	No	No	No
percent	Yes	No	No	No

As nouns, per centum and percent are synonyms defined as:

per centum and percent: a proportion in relation to a whole (which is usually the amount per hundred); ten percent

Other synonyms of per centum include pct, percentage.

per centum (noun)	percent (noun)
a proportion in relation to a whole (which is usually the amount per hundred); ten percent	a proportion in relation to a whole (which is usually the amount per hundred); ten percent