Source : Webster's Revised Unabridged Dictionary (1913)

Pirate \Pi"rate\, n. [L. pirata, Gr. ?, fr. ? to attempt,
   undertake, from making attempts or attacks on ships, ? an
   attempt, trial; akin to E. peril: cf. F. pirate. See
   {Peril}.]
   1. A robber on the high seas; one who by open violence takes
      the property of another on the high seas; especially, one
      who makes it his business to cruise for robbery or
      plunder; a freebooter on the seas; also, one who steals in
      a harbor.

   2. An armed ship or vessel which sails without a legal
      commission, for the purpose of plundering other vessels on
      the high seas.

   3. One who infringes the law of copyright, or publishes the
      work of an author without permission.

   {Pirate perch} (Zo["o]l.), a fresh-water percoid fish of the
      United States ({Aphredoderus Sayanus}). It is of a dark
      olive color, speckled with blackish spots.