VIII vs eighter

VIII and eighter both are nouns.

Word	Noun	Adjective	Verb	Adverb
VIII	Yes	No	No	No
eighter	Yes	No	No	No

As nouns, VIII and eighter are synonyms defined as:

Other synonyms of VIII include 8, eight, eighter from Decatur, octad, octet, octonary, ogdoad.

VIII (noun)	eighter (noun)
the cardinal number that is the sum of seven and one	the cardinal number that is the sum of seven and one