Definition of “authority” - Learner’s Dictionary

authority

noun us uk /ɔːˈθɒrəti/
Soldiers were given the authority to shoot, but only as a last resort.His school report remarked on his contempt for authority.Her voice took on a tone of authority.So is this a challenge to the authority of the President?He has an air of authority.
POWER [ U ]

B2 the official power to make decisions or to control other people:

a position of authority
[ + to do sth ] The investigators have the authority to examine all the company's records.
We need the support of someone in authority.
OFFICIAL GROUP [ C ]
QUALITY [ U ]

the quality of being confident and being able to control people:

She has an air of authority.
an authority on sth

someone who has a lot of knowledge about a particular subject:

She is an authority on seventeenth-century English literature.
→ See also local authority

(Definition of “authority” from the Cambridge Learner's Dictionary © Cambridge University Press)