1.NounPower or right to make or enforce rules, give orders, or impose obligation; or a position having such power or right.
"I have the authority to penalise the staff in my department, but not the authority to sack them.; Vigilantes may have the power to nab criminals, but they lack the authority.; She lost all respect and authority after turning up drunk at the meeting.; Respect my authority!"
2.NounPersons, regarded collectively, who occupy official positions of power; police or law enforcement.
"Authorities say the suspect fled on foot."
3.NounA reliable, definitive source of information on a subject.
"the world's foremost authority on orangutans; My cheap dictionary is not the authority on word derivations."
4.NounStatus as a trustworthy source of information, reputation for mastery or expertise; or claim to such status or reputation.
"Due to being inadequate for the deductive method of reasoning, the argument from authority is considered a logical fallacy."
5.NounOfficial permission; authorisation to act in some capacity on behalf of a ruling entity.
6.NounA government-owned agency that runs a revenue-generating activity for public benefit.
"New York Port Authority; Chicago Transit Authority"