A rigorous test means a very strict and demanding assessment or examination that requires significant effort, knowledge, and skill to pass. Full definition
It's a more rigorous test of how much a company would be worth if it had to be sold for scrap. (moneysense.ca)
This time, it is bringing on more partners so that it can handle the influx of products to be put through rigorous testing for a bronze, silver or gold rating. (treehugger.com)
We'll have to wait for more rigorous testing before we answer those questions. (tomsguide.com)