[countable, usually singular] a sudden steep fall or drop急剧下降；急转直下；暴跌◆Sales continued their nosedive, sinking by 14 per cent.销量持续暴跌，下降了 14%。◆The markets could take a nosedive, destroying consumer confidence.市场可能暴跌，从而摧毁消费者的信心。