来自knot,结。即多结的，引申词义复杂的。参照Gordian knot.

1. The new man-agement team faces some knotty problems.

新的管理团队面临一些棘手的问题。

来自柯林斯例句

2. the knotty roots of the old oak tree

盘根错节的老橡树根

来自《权威词典》

3. Under his leadership, many knotty problems were smoothly solved.

在他的领导下, 许多伤脑筋的问题都迎刃而解.

来自《现代汉英综合大词典》

4. She met with a lot of knotty problems.

她碰上了许多棘手的问题.

来自《简明英汉词典》

5. This is a knotty passage.

这是一段复杂难懂的文字.

来自《用法词典》