parallelopipedon vs parallelopiped

parallelopipedon and parallelopiped both are nouns.

Word	Noun	Adjective	Verb	Adverb
parallelopipedon	Yes	No	No	No
parallelopiped	Yes	No	No	No

As nouns, parallelopipedon and parallelopiped are synonyms defined as:

parallelopipedon and parallelopiped: a prism whose bases are parallelograms

Other synonyms of parallelopipedon include parallelepiped, parallelepipedon.

parallelopipedon (noun)	parallelopiped (noun)
a prism whose bases are parallelograms	a prism whose bases are parallelograms