DuckCorp Dico

Found one definition

1.                 From The Collaborative International Dictionary of English v.0.48:
                   
   
   
                   
                     
   Fac \Fac\ (f[a^]k), n. [Abbrev. of facsimile.]
      A large ornamental letter used, esp. by the early printers,
      at the commencement of the chapters and other divisions of a
      book. --Brande & C.
      [1913 Webster]