parallelepipedon vs parallelopiped

parallelepipedon and parallelopiped both are nouns.

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

As nouns, parallelepipedon and parallelopiped are synonyms defined as:

parallelepipedon and parallelopiped: a prism whose bases are parallelograms

Other synonyms of parallelepipedon include parallelepiped, parallelopipedon.

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