When gross domestic product (GDP) growth slides back to negative after a quarter or two of positive growth. A double-dip recession refers to a recession followed by a short-lived recovery, followed by another recession.
The causes for a double-dip recession vary but often include a slowdown in the demand for goods and services because of layoffs and spending cutbacks from the previous downturn.
A double-dip (or even triple-dip) is a worst-case scenario. Fear that the economy will move back into a deeper and longer recession makes recovery even more difficult.
Source: http://www.investopedia.com/terms/d/doublediprecession.asp
