1. Synonyms for Callously include brutally, coldly, hardheartedly, harshly, heartlessly, indifferently, insensitively, obdurately, unfeelingly and carelessly

2. Callously adverb heartlessly, coldly, harshly, brutally, insensitively, obdurately, unfeelingly, soullessly, hardheartedly He is accused of Callously ill-treating his wife

3. Cruelly, fiercely, savagely, ruthlessly, viciously, mercilessly, ferociously, remorselessly, in cold blood, callously, murderously, pitilessly, heartlessly, inhumanly, barbarously, brutishly, barbarically, hardheartedly Her real parents had been Brutally murdered.