Source : Webster's Revised Unabridged Dictionary (1913)

Impatience \Im*pa"tience\n. [OE. impacience, F. impatience, fr.
   L. impatientia.]
   The quality of being impatient; want of endurance of pain,
   suffering, opposition, or delay; eagerness for change, or for
   something expected; restlessness; chafing of spirit;
   fretfulness; passion; as, the impatience of a child or an
   invalid.

         I then, . . . Out of my grief and my impatience,
         Answered neglectingly.                   --Shak.

         With huge impatience he inly swelt More for great
         sorrow that he could not pass, Than for the burning
         torment which he felt.                   --Spenser.

Source : WordNet®

impatience
     n 1: a lack of patience; irritation with anything that causes
          delay [syn: {restlessness}]
     2: a restless desire for change and excitement
     3: a dislike of anything that causes delay [ant: {patience}]