"unofficially" in the adverb sense
1. unofficially, on the side
without official authorization
"he had made some money on the side"
2. unofficially
not in an official capacity
"unofficially, he serves as the treasurer"
Source: WordNet® (An amazing lexical database of English)
Princeton University "About WordNet®."
WordNet®. Princeton University. 2010.
View WordNet® License