Source : Webster's Revised Unabridged Dictionary (1913)

Stability \Sta*bil"i*ty\, n. [L. stabilitas; cf. F.
   stabilit['e]. See {Stable}, a.]
   1. The state or quality of being stable, or firm; steadiness;
      firmness; strength to stand without being moved or
      overthrown; as, the stability of a structure; the
      stability of a throne or a constitution.

   2. Steadiness or firmness of character, firmness of
      resolution or purpose; the quality opposite to
      {fickleness}, {irresolution}, or {inconstancy}; constancy;
      steadfastness; as, a man of little stability, or of
      unusual stability.

   3. Fixedness; -- as opposed to {fluidity}.

            Since fluidness and stability are contary qualities.
                                                  --Boyle.

   Syn: Steadiness; stableness; constancy; immovability;
        firmness.

Source : WordNet®

stability
     n 1: the quality or attribute of being firm and steadfast [syn: {stableness}]
          [ant: {instability}, {instability}]
     2: a stable order [ant: {instability}]
     3: the quality of being free from change or variation [syn: {constancy}]
        [ant: {inconstancy}]