Synonyms and related words :
cheeseparing, culpably negligent, derelict, frugal, frugal to excess, inadvertent, inattentive, laissez-faire, lax, loose, neglectful, neglecting, negligent, noninterfering, nonrestrictive, off-guard, overfrugal, overly permissive, parsimonious, penny-wise, penny-wise and pound-foolish, permissive, procrastinating, relaxed, remiss, scrimping, skimping, slack, slighting, slurring, sparing, stinting, too frugal, uncircumspect, unguarded, unrigorous, unwary, unwatchful