un ‧ of ‧ fi ‧ cial /ˌʌnəˈfɪʃ ə l◂/ BrE AmE adjective
[ Word Family: noun : ↑ office , ↑ officer , ↑ official , ↑ officialdom , ↑ officialese , ↑ officiousness ; adverb : ↑ officially ≠ ↑ unofficially , ↑ officiously ; adjective : ↑ official ≠ ↑ unofficial , ↑ officious ; verb : ↑ officiate ]
1 . done or produced without formal approval or permission:
Hodges wrote an unofficial biography of the artist.
2 . not done as part of your job:
The President made an unofficial visit to the Senator’s house.
—unofficially adverb