Source : Webster's Revised Unabridged Dictionary (1913)

Occasionally \Oc*ca"sion*al*ly\, adv.
   In an occasional manner; on occasion; at times, as
   convenience requires or opportunity offers; not regularly.
   --Stewart.

         The one, Wolsey, directly his subject by birth; the
         other, his subject occasionally by his preferment.
                                                  --Fuller.

Source : WordNet®

occasionally
     adv : now and then or here and there; "he was arrogant and
           occasionally callous"; "open areas are only
           occasionally interrupted by clumps of trees"; "they
           visit New York on occasion"; "now and again she would
           take her favorite book from the shelf and read to us";
           "as we drove along, the beautiful scenery now and then
           attracted his attention" [syn: {on occasion}, {once in
           a while}, {now and then}, {now and again}, {at times},
           {from time to time}]