gruelling
adj. 折磨人的；繁重累人的；使人精疲力尽的
n. 惩罚；痛打
v. 累垮；惩罚（gruel 的 ing 形式）
例句
I've had a gruelling day.
我一天下来累得筋疲力尽。
《牛津词典》
After the gruelling test, he felt totally spent.
紧张的考试过后，他感觉筋疲力尽了。
He had complained of exhaustion after his gruelling schedule over the past week.
完成上星期紧张的日程安排后，他抱怨自己已筋疲力尽。
《柯林斯英汉双解大词典》
