noun
failure, lack, delinquency, dereliction, omission, error, failure to act, inaction, failure to pay, nonpayment, oversight, neglect, negligence, shortcoming, want, inadequacy, insufficiency, failure to appear, lapse, fault, nonfeasance, nonfulfillment, arrears, arrearage; see also omission 1.
Antonyms discharge, fulfillment, payment.
in default of