The Collaborative International Dictionary of English v.0.48:

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.
   [1913 Webster]

   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.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Dovetail \Dove"tail`\, v. t. [imp. & p. p. Dovetailed; p. pr.
   & vb. n. Dovetailing.]
   1. (Carp.)
      (a) To cut to a dovetail.
      (b) To join by means of dovetails.
          [1913 Webster]

   2. To fit in or connect strongly, skillfully, or nicely; to
      fit ingeniously or complexly.
      [1913 Webster]

            He put together a piece of joinery so crossly
            indented and whimsically dovetailed . . . that it
            was indeed a very curious show.       --Burke.
      [1913 Webster]

WordNet (r) 3.0 (2006):

dovetail
    n 1: a mortise joint formed by interlocking tenons and mortises
         [syn: dovetail, dovetail joint]
    v 1: fit together tightly, as if by means of a dovetail