From Longman Dictionary of Contemporary Englishnegative equityˌnegative ˈequity noun [uncountable] British English a situation in which someone owes more money on a mortgage (=arrangement to borrow money to pay for a house) than they would receive if they sold their house
Examples from the Corpus
negative equity• Dave Escott bought at the height of the boom, and any back rent will only add to his negative equity.• The risk of another plague of negative equity in the highly-priced areas must now be significant.• Those with negative equity clearly benefit from higher prices, but many others gain from lower ones.From Longman Business Dictionarynegative equityˌnegative ˈequity1[uncountable]FINANCE when an asset, usually property, bought by a borrower with a loan is worth less than the loan remaining to be paidthe growing number of home owners with negative equity2[uncountable]ACCOUNTINGFINANCE when a company’s liabilities are more than its assetsThe level of bad debts at some Thai banks may mean that some have negative equity. → equity 