残酷【ざんこく】
cruel, brutal, ruthless, merciless, inhuman
過酷【かこく】
severe, harsh, hard, cruel, rigorous
冷酷【れいこく】
cruelty, coldheartedness, relentless, ruthless
酷暑【こくしょ】
intense heat, severe heat
酷似【こくじ】
resembling closely, being strikingly similar, bearing a strong likeness
酷評【こくひょう】
severe criticism, sharp criticism, scathing criticism, diatribe, panning
酷使【こくし】
exploitation, overuse, abuse
酷寒【こっかん】
severe cold, intense cold, bitter cold