Source : Webster's Revised Unabridged Dictionary (1913)

Dovetail \Dove"tail`\, n. (Carp.)
   A flaring tenon, or tongue (shaped like a bird's tail
   spread), and a mortise, or socket, into which it fits
   tightly, making an interlocking joint between two pieces
   which resists pulling a part in all directions except one.

   {Dovetail molding} (Arch.), a molding of any convex section
      arranged in a sort of zigzag, like a series of dovetails.
      

   {Dovetail saw} (Carp.), a saw used in dovetailing.