Stress Test is a form of testing to determine the stability of a system. In the financial world, a company may do stress testing where they examine how strong a financial instrument is in certain occurrences.
Additional meaning of Stress Test:
In the US the Supervisory Capital Assessment Program is often referred to as the bank stress tests (although many companies involved were not banks). This program determined if financial organizations had sufficient capital to withstand the recession. A banking stress test was conducted in the European Union in 2010 with the aim of assessing the financial strength of European banks under different adverse scenarios.