Source : Webster's Revised Unabridged Dictionary (1913)

Ceremonially \Cer`e*mo"ni*al*ly\, adv.
   According to rites and ceremonies; as, a person ceremonially
   unclean.

Source : WordNet®

ceremonially
     adv 1: in a ceremonious manner; "my mother advised her children
            ceremoniouslly" [syn: {ceremoniously}] [ant: {unceremoniously}]
     2: in a ceremonial manner; "he was ceremonially sworn in as
        President" [syn: {ritually}]