Synonyms and related words :
carelessly, heedlessly, inconsiderately, indeliberately, involuntarily, lightly, negligently, permissively, remissly, scampingly, skimpingly, slightingly, slurringly, thoughtlessly, unadvisedly, uncalculatedly, undesignedly, unintentionally, unpremeditatedly, unreasoningly, unrigorously, unthinkingly, unthoughtfully, without premeditation, without willing