normal vs abnormal

normal is a noun but abnormal is not a noun.

normal (noun)	abnormal (noun)
something regarded as a normative example

normal (adjective)	abnormal (adjective)
conforming with or constituting a norm or standard or level or type or social norm; not abnormal	not normal; not typical or usual or regular or conforming to a norm
in accordance with scientific laws	departing from the normal in e.g. intelligence and development
being approximately average or within certain limits in e.g. intelligence and development	much greater than the normal
forming a right angle