Source : Webster's Revised Unabridged Dictionary (1913)

Pentagram \Pen"ta*gram\, n. [Gr. ?, neut. of ? having five
   lines. See {Penta-}, and {-gram}.]
   A pentacle or a pentalpha. ``Like a wizard pentagram.''
   --Tennyson.

Source : WordNet®

pentagram
     n : a star with 5 points; formed by 5 straight lines between the
         vertices of a pentagon and enclosing another pentagon
         [syn: {pentacle}]