From Longman Dictionary of Contemporary Englishunofficialun‧of‧fi‧cial /ˌʌnəˈfɪʃəl◂/ ●○○ adjective 1 LET/ALLOW#done or produced without formal approval or permission Hodges wrote an unofficial biography of the artist.2 PUBLIC/NOT PRIVATE#not done as part of your job The president made an unofficial visit to the Senator’s house. —unofficially adverb
Examples from the Corpusunofficial• Released 25 years ago, the recording became the unofficial anthem of my first-ever election campaign.• Even expressways were planned as man-made barriers, the unofficial borders.• This is an unobtrusive way of keeping expensive unofficial calls to the minimum.• After the official Red Square parade there were two unofficial marches in Moscow, sanctioned by the city soviet.• An informal and unofficial market began to develop.• Feinstein emphasized that the trip was "an unofficial mission."• And as you head out to grab lunch, it seems as if an unofficial national holiday has been declared.• Now Bush has regained his position as frontrunner by winning the first unofficial rounds of the campaign.• Unofficial sources say that over 100 people were shot dead in the rioting.• She seems to have become the unofficial spokesman for the group.• "Take Me Home, Country Road" became West Virginia's unofficial state song.• The Prime Minister discussed the mater with his German counterpart on an unofficial visit to his home last month.• Artists who had once been considered unofficial were later accepted into the official art world and viceversa.From Longman Business Dictionaryunofficialun‧of‧fi‧cial /ˌʌnəˈfɪʃəl◂/ adjective1without formal approval and permission from the organization or person in authorityHe made his complaint through unofficial channels.2not made publicly known as part of an official planOur unofficial policy is to grant two days’ paternity leave. —unofficially adverbThe trade union was unofficially formed in 1972.