/tu ækt baɪ əˈθɔrɪti/ – Phrase
Definition: hành động theo quyền hạn.
A more thorough explanation: “To act by authority” means to perform an action or make a decision based on the power or permission granted by a legal or official source, such as a law, regulation, or governing body.
Example: The police officer was authorized to search the premises by the warrant issued by the judge.