gruelling
gruel·ling
adjective
1.
characterized by toilsome effort to the point of exhaustion; especially physical effort
- “worked their arduous way up the mining valley”
- “a grueling campaign”
- “hard labor”
- “heavy work”
- “heavy going”
- “spent many laborious hours on the project”
- “set a punishing pace”
Origin
From present participle of gruel (“to exhaust, punish”), from gruel (noun).
WordNet 2.1 (Princeton University). Wiktionary (CC BY-SA). CMU Pronouncing Dictionary. WordNet 2.1 Copyright Princeton University. All rights reserved. Wiktionary content is available under the Creative Commons Attribution-ShareAlike Licence.