macrencephaly vs abnormality

macrencephaly and abnormality both are nouns.

Word	Noun	Adjective	Verb	Adverb
macrencephaly	Yes	No	No	No
abnormality	Yes	No	No	No

As nouns, abnormality is a hypernym of macrencephaly; that is, abnormality is a word with a broader meaning than macrencephaly:

macrencephaly: an abnormally large braincase
abnormality: an abnormal physical condition resulting from defective genes or developmental deficiencies

Other hypernyms of macrencephaly include abnormalcy.

macrencephaly (noun)	abnormality (noun)
an abnormally large braincase	behavior that breaches the rule or etiquette or custom or morality
	marked strangeness as a consequence of being abnormal
	retardation sufficient to fall outside the normal range of intelligence
	an abnormal physical condition resulting from defective genes or developmental deficiencies