adjective

1. of or holding an office, or position of authority
2. by, from, or with the proper authority; authorized or authoritative an official request
3. in a formal or ceremonious manner, often involving persons of authority an official welcome to the city
4. formally set or prescribed the official date of publication
5. Med., Pharmacy contained in the current pharmacopeia; authorized for use in medicine

Etymology: OFr < LL officialis

noun

1. a person holding office, esp. public office
2. Sports one who supervises an athletic contest, as a referee, umpire, etc.