THESAURUS
disregardful
airy, apathetic, arrogant, ataractic, audacious, behindhand, blase, bold, brash, brassy, brazen, bumptious, careless, casual, challenging, cheeky, cocky, contemptuous, cursory, daring, defiant, defying, degage, derisive, devil-may-care, disdainful, disinterested, dispassionate, disregardant, distracted, distrait, easygoing, flippant, forgetful, free and easy, greatly daring, heedless, impertinent, impudent, inadvertent, inattentive, inconsiderate, inconstant, incurious, indifferent, inexcitable, inobservant, insolent, insouciant, lackadaisical, lazy, listless, mindless, negligent, nonadherent, nonchalant, noncompliant, nonconforming, nonobservant, oblivious, offhand, perfunctory, pert, pococurante, reckless, regardless, regardless of consequences, remiss, respectless, saucy, slack, tactless, thoughtless, turned-off, unaccommodating, unanxious, uncomplaisant, uncompliant, unconcerned, unconforming, uncooperative, undiplomatic, undiscriminating, unfaithful, unheedful, unheeding, unhelpful, uninterested, unloyal, unmarking, unmindful, unnoticing, unnoting, unobliging, unobservant, unobserving, unprepared, unready, unremarking, unsolicitous, untactful, unthinking, unthoughtful, untrue
