Source : Webster's Revised Unabridged Dictionary (1913)

Anniversary \An`ni*ver"sa*ry\, a. [L. anniversarius; annus year
   + vertere, versum, to turn: cf. F. anniversaire.]
   Returning with the year, at a stated time; annual; yearly;
   as, an anniversary feast.

   {Anniversary day} (R. C. Ch.). See {Anniversary}, n., 2.

   {Anniversary week}, that week in the year in which the annual
      meetings of religious and benevolent societies are held in
      Boston and New York. [Eastern U. S.]