as hard as nails1 someone who is hard as nails seems to have no feelings such as fear or sympathy 无所畏惧的；冷酷无情的(as) hard as nails• Willie O'Connor is as hard as nails and Liam Simpson takes no prisoners.• Hard as nails he may be but don't let anyone tell you Hank hasn't got a sense of humour.• Beautiful but hard as nails, she'd thought then.
→ (as) hard as nails at hard1(16)
2 very tough and not easily frightened, or not caring about the effects of your actions on other people 铁石心肠的，冷酷无情的；非常坚强的as hard/tough as nails• Willie O'Connor is as hard as nails and Liam Simpson takes no prisoners.
→ as hard/tough as nails at nail1(2)