permission vs authority

permission and authority both are nouns.

Word	Noun	Adjective	Verb	Adverb
permission	Yes	No	No	No
authority	Yes	No	No	No

As nouns, authority is a hyponym of permission; that is, authority is a word with a more specific, narrower meaning than permission:

permission (noun)	authority (noun)
the act of giving a formal (usually written) authorization	the power or right to give orders or make decisions
approval to do something	official permission or approval
	freedom from doubt; belief in yourself and your abilities
	an authoritative written work
	an administrative unit of government
	an expert whose views are taken as definitive
	(usually plural) persons who exercise (administrative) control over others