/ˈrɪɡərəs/ – adjective
Definition: nghiêm ngặt, chặt chẽ
A more thorough explanation: 1. difficult; demanding
2. extremely careful; thorough
3. strictly applied
Example: 1. He was subjected to a rigorous cross-examination on the witness stand.
2. This further emphasises the continuing need for rigorous controls on GM (=genetically modified) material.
3. While the government has done well in providing a positive incentive for timber producers through FLEGT licences, it needs to be complemented with more rigorous law enforcement.