[, ]a situation where sth fails or becomes weaker in a sudden and dramatic way 融化(过程);突然垮掉◆The country is in economic meltdown. 这个国家经济崩溃了。◆fears of a meltdown in consumer spending 对消费者支出骤减的担忧◆a meltdown on Wall Street (= when the prices of US shares fall suddenly) 华尔街股市崩盘