Source : Webster's Revised Unabridged Dictionary (1913)

Officially \Of*fi"cial*ly\, adv.
   By the proper officer; by virtue of the proper authority; in
   pursuance of the special powers vested in an officer or
   office; as, accounts or reports officially vertified or
   rendered; letters officially communicated; persons officially
   notified.

Source : WordNet®

officially
     adv 1: in an official role; "officially, he is in charge";
            "officially responsible" [ant: {unofficially}]
     2: with official authorization; "the club will be formally
        recognized" [syn: {formally}]