Source : Webster's Revised Unabridged Dictionary (1913)

Itch \Itch\, v. i. [imp. & p. p. {Itched}; p. pr. & vb. n.
   {Itching}.] [OE. icchen, ?icchen, AS. giccan; akin to D.
   jeuken, joken, G. jucken, OHG. jucchen.]
   1. To have an uneasy sensation in the skin, which inclines
      the person to scratch the part affected.

            My mouth hath itched all this long day. --Chaucer.

   2. To have a constant desire or teasing uneasiness; to long
      for; as, itching ears. ``An itching palm.'' --Shak.

Source : WordNet®

itching
     n : an irritating cutaneous sensation that produces a desire to
         scratch [syn: {itch}, {itchiness}]