1. 严罚/严惩：grueling /严罚/严惩/ | gruelling /严罚/严惩/ | gruesome /可怕的/

2. 繁重而累人的：legacy 祖先遗留下之物 遗赠物 | gruelling 繁重而累人的 | beholder 旁观者

3. 使人精疲力尽的：fateful 决定性的,宿命的 | gruelling 使人精疲力尽的 | grim 严峻的,不景气的

4. 重罚的; 严惩的 (形)：grueling 劳累; 苛待, 惩罚 (名) | gruelling 重罚的; 严惩的 (形) | gruesome 可怕的, 阴森的, 令人毛骨悚然的 (形)

adj

1. characterized by effort to the point of exhaustion
especially physical effort

e.g. 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

Synonym: arduousbackbreakinggruelinghardheavylaboriousoperosepunishingtoilsome