Source : Webster's Revised Unabridged Dictionary (1913)

Rankle \Ran"kle\, v. i. [imp. & p. p. {Rankled}; p. pr. & vb. n.
   {Rankling}.] [From {Rank}, a.]
   1. To become, or be, rank; to grow rank or strong; to be
      inflamed; to fester; -- used literally and figuratively.

            A malady that burns and rankles inward. --Rowe.

            This would have left a rankling wound in the hearts
            of the people.                        --Burke.

   2. To produce a festering or inflamed effect; to cause a
      sore; -- used literally and figuratively; as, a splinter
      rankles in the flesh; the words rankled in his bosom.

Rankle \Ran"kle\, v. t.
   To cause to fester; to make sore; to inflame. [R.] --Beau. &
   Fl.

Source : WordNet®

rankle
     v : gnaw into; make resentful or angry; "The unjustice rankled
         her"; "his resentment festered" [syn: {eat into}, {fret},
          {grate}]