Source : Webster's Revised Unabridged Dictionary (1913)

Dagger \Dag"ger\, v. t.
   To pierce with a dagger; to stab. [Obs.]

Dagger \Dag"ger\, n. [Perh. from diagonal.]
   A timber placed diagonally in a ship's frame. --Knight.

Dagger \Dag"ger\ (-g[~e]r), n. [Cf. OE. daggen to pierce, F.
   daguer. See {Dag} a dagger.]
   1. A short weapon used for stabbing. This is the general
      term: cf. {Poniard}, {Stiletto}, {Bowie knife}, {Dirk},
      {Misericorde}, {Anlace}.

   2. (Print.) A mark of reference in the form of a dagger
      [[dagger]]. It is the second in order when more than one
      reference occurs on a page; -- called also {obelisk}.

   {Dagger moth} (Zo["o]l.), any moth of the genus {Apatalea}.
      The larv[ae] are often destructive to the foliage of fruit
      trees, etc.

   {Dagger of lath}, the wooden weapon given to the Vice in the
      old Moralities. --Shak.

   {Double dagger}, a mark of reference [[dag]] which comes next
      in order after the dagger.

   {To look, or speak}, {daggers}, to look or speak fiercely or
      reproachfully.

Source : WordNet®

dagger
     n 1: a short knife with a pointed blade used for piercing or
          stabbing [syn: {sticker}]
     2: a character used in printing to indicate a cross reference
        or footnote [syn: {obelisk}]