"Negative equity" means owing more money on something (like a house or a car) than it is currently worth. It's a situation where the value of an asset is lower than the amount of debt or loan associated with it. Full definition
With just 3 % down you could be in negative equity in a heart beat. (money.stackexchange.com)
After only 1 year, I rolled a bunch of negative equity into a new car, because I just couldn't put up with it anymore. (edmunds.com)
The actual real estate market is much worse even than the present price statistics show, because many people are frozen in with negative equity. (michael-hudson.com)