noun
- a person or thing that gruels; something that is grueling or exhausting
Usage: informal; often used in sports or fitness contexts
Examples
- That marathon was a real grueller—I'm still sore three days later.
- The final exam turned out to be a grueller that nobody expected.
- Training for the Olympics is a grueller that tests both body and mind.
- The cross-country hike proved to be a grueller for the unprepared hikers.