[ir.re.spon.si.ble] adj (1648): not responsible: as a: not answerable to higher authority "an ~ dictatorship" b: said or done with no sense of responsibility "~ accusations" c: lacking a sense of responsibility d: unable esp. mentally or financially to bear responsibility -- ir.re.spon.si.bil.i.ty n -- ir.re.spon.si.ble.ness n -- ir.re.spon.si.bly adv
[2]irresponsible n (1894): one that is irresponsible