rigorous
adjectiveUK /ˈrɪɡ.ər.əs/
US /ˈrɪɡ.ɚ.əs/
Very careful and strict about doing things exactly right.
The teacher gave us a rigorous test that made us think hard.
RELATED WORDS
OTHER MEANINGS
2. Very hard and tiring to do.
Training for the marathon was a rigorous process.
3. Following rules or standards very closely.
The lab follows rigorous safety rules.
4. Harsh or severe, like extreme weather.
They survived a rigorous winter in the mountains.