Antonyms of adv unofficially

1 of 2 senses of unofficially

Sense 2
unofficially -- (not in an official capacity; "unofficially, he serves as the treasurer")
       Antonym of officially (Sense 1)
      => officially -- (in an official role; "officially, he is in charge"; "officially responsible")

Synonyms of adv unofficially

2 senses of unofficially

Sense 1
unofficially, on the side -- (without official authorization; "he had made some money on the side")

Sense 2
unofficially -- (not in an official capacity; "unofficially, he serves as the treasurer")