1. people or organizations having power or control in a particular area
Usage: plural form
2. experts who are recognized as having special knowledge in a subject
Usage: plural form

Examples

• The local authorities closed the park due to safety concerns.
• Students must report any incidents to the school authorities.
• The authorities are investigating the cause of the accident.
• Immigration authorities checked all passengers at the border.
• Leading authorities on climate change attended the conference.
• She consulted several authorities before writing her research paper.
• The book cites authorities from multiple universities.