Source : Webster's Revised Unabridged Dictionary (1913)

Nonpayment \Non*pay"ment\, n.
   Neglect or failure to pay.

Source : WordNet®

nonpayment
     n 1: act of failing to meet a financial obligation [syn: {default},
           {nonremittal}]
     2: loss resulting from failure of a debt to be paid [syn: {default},
         {nonremittal}] [ant: {payment}]
     3: the deliberate act of failing to pay money; "his evasion of
        all his creditors"; "he was indicted for nonpayment" [syn:
         {evasion}] [ant: {payment}]