Source : Webster's Revised Unabridged Dictionary (1913)

Decollation \De`col*la"tion\, n. [L. decollatio: cf. F.
   d['e]collation.]
   1. The act of beheading or state of one beheaded; --
      especially used of the execution of St. John the Baptist.

   2. A painting representing the beheading of a saint or
      martyr, esp. of St. John the Baptist.