[syn: derelict, delinquent, neglectful, remiss]
The Collaborative International Dictionary of English v.0.48:
Neglectful \Neg*lect"ful\, a.
   Full of neglect; heedless; careless; negligent; inattentive;
   indifferent. --Pope.
   [1913 Webster]
         A cold and neglectful countenance.       --Locke.
   [1913 Webster]
         Though the Romans had no great genius for trade, yet
         they were not entirely neglectful of it. --Arbuthnot.
   [1913 Webster] -- Neg*lect"ful*ly, adv. --
   Neg*lect"ful*ness, n.
   [1913 Webster]
WordNet (r) 3.0 (2006):
neglectful
    adj 1: not showing due care or attention; "inattentive
           students"; "an inattentive babysitter"; "neglectful
           parents" [syn: inattentive, neglectful]
    2: failing in what duty requires; "derelict (or delinquent) in
       his duty"; "neglectful of his duties"; "remiss of you not to
       pay your bills" [syn: derelict, delinquent, neglectful,
       remiss]
Moby Thesaurus II by Grady Ward, 1.0:
32 Moby Thesaurus words for "neglectful":
   behindhand, careless, culpably negligent, delinquent, derelict,
   disregardful, inadvertent, inattentive, laissez-faire, lax, loose,
   neglecting, negligent, noninterfering, nonrestrictive, off-guard,
   overly permissive, permissive, procrastinating, regardless,
   relaxed, remiss, scamping, skimping, slack, slighting, slurring,
   uncircumspect, unguarded, unrigorous, unwary, unwatchful