Synonyms and related words :
accidia, acedia, apathy, ataraxia, ataraxy, carelessness, casualness, choicelessness, detachment, disinterest, dispassion, disregard, disregardfulness, easygoingness, heedlessness, inattention, incuriosity, inexcitability, insouciance, lack of affect, lackadaisicalness, listlessness, mindlessness, negligence, no choice, nonchalance, only choice, pococurantism, recklessness, regardlessness, sloth, unanxiousness, unconcern, unmindfulness, unsolicitousness