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

See also: official

Antonym: unofficially

• unchangeable
• unchangeableness
• unchangeably
• unchanged
• unchanging
• unchangingness
• unchaperoned
• uncharacteristic
• uncharacteristically
• uncharged
• uncharitable
• uncharitably
• uncharted
• unchartered
• unchaste
• unchastened
• uncheckable
• unchecked
• uncheerful
• uncheerfulness
• unchewable
• unchivalrous
• unchivalrously
• unchristian
• unchristianly