The Collaborative International Dictionary of English v.0.48:

Delinquency \De*lin"quen*cy\, n.; pl. Delinquencies. [L.
   delinquentia, fr. delinquens.]
   Failure or omission of duty; a fault; a misdeed; an offense;
   a misdemeanor; a crime.
   [1913 Webster]

         The delinquencies of the little commonwealth would be
         represented in the most glaring colors.  --Motley.
   [1913 Webster]

WordNet (r) 3.0 (2006):

delinquency
    n 1: nonpayment of a debt when due
    2: a tendency to be negligent and uncaring; "he inherited his
       delinquency from his father"; "his derelictions were not
       really intended as crimes"; "his adolescent protest consisted
       of willful neglect of all his responsibilities" [syn:
       delinquency, dereliction, willful neglect]
    3: an antisocial misdeed in violation of the law by a minor
       [syn: delinquency, juvenile delinquency]

Moby Thesaurus II by Grady Ward, 1.0:

144 Moby Thesaurus words for "delinquency":
   aberrance, aberrancy, abnormality, amorality, arrear, arrearage,
   arrears, atrocity, backsliding, bad debt, breach, carnality, crime,
   crime against humanity, criminality, deadly sin, decline,
   defalcation, default, defection, defectiveness, deficit,
   delinquence, dereliction, deviance, deviancy, disconformity,
   dishonor, dishonoring, disregard, enormity, error, evil,
   evil nature, failure, falling short, fault, felony, genocide,
   guilty act, heavy sin, illegality, immorality, imperfection,
   improperness, impropriety, impurity, inadequacy, inappropriateness,
   inattention, incorrectness, indecorousness, indecorum,
   indiscretion, inexpiable sin, inferiority, infraction, iniquity,
   injury, injustice, inobservance, insufficiency, lapse, laxity,
   malefaction, malfeasance, malum, minor wrong, misdeed, misdemeanor,
   misfeasance, moral delinquency, mortal sin, neglect, negligence,
   nonadherence, noncompliance, nonconformance, nonconformity,
   nondischarge of debts, nonfeasance, nonfulfillment, nonobservance,
   nonpayment, nonperformance, nonremittal, offense, omission,
   outrage, oversight, peccability, peccadillo, peccancy, prodigality,
   protest, protested bill, recidivism, repudiation, short measure,
   shortage, shortcoming, shortfall, sin, sin of commission,
   sin of omission, sinful act, sinfulness, slight, slip, slump, tort,
   transgression, trespass, trip, unangelicalness, unchastity,
   uncleanness, uncollectible, underage, unfitness, unfittingness,
   ungodliness, ungoodness, unlawfulness, unmorality, unobservance,
   unrighteousness, unsaintliness, unseemliness, unsuitability,
   unutterable sin, unvirtuousness, venial sin, vice, viciousness,
   violation, wantonness, waywardness, weakness, wickedness, wrong,
   wrongdoing, wrongfulness, wrongness