1. In an official role
   "officially, he is in charge"; "officially responsible" 
2. With official authorization
   - formally

See also: official

Antonym: unofficially

• interchangeable
• interchangeableness
• interchangeably
• interchurch
• intercity
• intercollegiate
• intercolumniation
• intercom
• intercom speaker
• intercommunicate
• intercommunication
• intercommunication system
• intercommunion
• interconnect
• interconnected
• interconnectedness
• interconnection
• intercontinental
• intercontinental ballistic missile
• interconvertible
• intercostal
• intercostal artery
• intercostal muscle
• intercostal vein
• intercourse