Origin: Latin suffix -al
Unofficial has 3 different meanings across 1 category:
not having official authority or sanction
"a sort of unofficial mayor"
"an unofficial estimate"
"he participated in an unofficial capacity"
Not officially established.
"The unofficial meeting took place in a private room behind the main office door."
In plain English: Unofficial means something that is not officially recognized, approved, or part of an organization's formal rules.
"The team celebrated with an unofficial victory parade before they had actually won the game."
The word unofficial combines the prefix un-, meaning not or opposite of, with official to describe something that is not authorized by an authority. It entered English as a straightforward negation of the term official to denote actions or status lacking formal recognition.