Source : Webster's Revised Unabridged Dictionary (1913)

Poach \Poach\, v. t. [imp. & p. p. {Poached}; p. pr. & vb. n.
   {Poaching}.] [F. pocher to place in a pocket, to poach eggs
   (the yolk of the egg being as it were pouched in the white),
   from poche pocket, pouch. See {Pouch}, v. & n.]
   1. To cook, as eggs, by breaking them into boiling water;
      also, to cook with butter after breaking in a vessel.
      --Bacon.

   2. To rob of game; to pocket and convey away by stealth, as
      game; hence, to plunder. --Garth.

Poach \Poach\, v. i.
   To steal or pocket game, or to carry it away privately, as in
   a bag; to kill or destroy game contrary to law, especially by
   night; to hunt or fish unlawfully; as, to poach for rabbits
   or for salmon.

Poach \Poach\, v. t. [Cf. OF. pocher to thrust or dig out with
   the fingers, to bruise (the eyes), F. pouce thumb, L. pollex,
   and also E. poach to cook eggs, to plunder, and poke to
   thrust against.]
   1. To stab; to pierce; to spear, \as fish. [Obs.] --Carew.

   2. To force, drive, or plunge into anything. [Obs.]

            His horse poching one of his legs into some hollow
            ground.                               --Sir W.
                                                  Temple.

   3. To make soft or muddy by trampling --Tennyson.

   4. To begin and not complete. [Obs.] --Bacon.

Poach \Poach\, v. i.
   To become soft or muddy.

         Chalky and clay lands . . . chap in summer, and poach
         in winter.                               --Mortimer.

Source : WordNet®

poach
     v 1: hunt illegally; "people are poaching elephants for their
          ivory"
     2: cook in a simmering liquid; "poached apricots"