2ADJ-GRADED [usually ADJ n](問題)棘手的,複雜難解的,令人頭疼的 If you describe a problem as thorny, you mean that it is very complicated and difficult to solve, and that people are often unwilling to discuss it. (問題)棘手的,複雜難解的,令人頭疼的
...the thorny issue of immigration policy.
移民政策這個棘手問題
It is essential that we tackle this thorny problem.