Source : Webster's Revised Unabridged Dictionary (1913)

Irresistibility \Ir`re*sist`i*bil"i*ty\, n. [Cf. F.
   irr['e]sistibilit['e].]
   The quality or state of being irrestible, irresistibleness.

Source : WordNet®

irresistibility
     n : the quality of being overpowering and impossible to resist
         [syn: {irresistibleness}]