acephaly vs acephalia

acephaly and acephalia both are nouns.

Word	Noun	Adjective	Verb	Adverb
acephaly	Yes	No	No	No
acephalia	Yes	No	No	No

As nouns, acephaly and acephalia are synonyms defined as:

acephaly and acephalia: absence of the head (as in the development of some monsters)

Other synonyms of acephaly include acephalism.

acephaly (noun)	acephalia (noun)
absence of the head (as in the development of some monsters)	absence of the head (as in the development of some monsters)