Source : Webster's Revised Unabridged Dictionary (1913)

Sticking \Stick"ing\,
   a. & n. from {Stick}, v.

   {Sticking piece}, a piece of beef cut from the neck. [Eng.]
      

   {Sticking place}, the place where a thing sticks, or remains
      fast; sticking point.

            But screw your courage to the sticking place, And
            we'll not fail.                       --Shak.

   {Sticking plaster}, an adhesive plaster for closing wounds,
      and for similar uses.

   {Sticking point}. Same as {Sticking place}, above.

Source : WordNet®

sticking point
     n : a point at which an impasse arises in progress towrd and
         agreement or a goal