proconsul vs proconsular

proconsul is a noun but proconsular is not a noun.

Word	Noun	Adjective	Verb	Adverb
proconsul	Yes	No	No	No
proconsular	No	Yes	No	No

proconsul (noun)	proconsular (noun)
an anthropoid ape of the genus Proconsul
a provincial governor of consular rank in the Roman Republic and Roman Empire
an official in a modern colony who has considerable administrative power

proconsul (adjective)	proconsular (adjective)
	of or relating to or typical of a proconsul