thorny
US /ˈθɔːr.ni/
UK /ˈθɔːr.ni/

1.
2.
棘手的, 複雜的, 困難的
causing difficulties or disagreements; complex and difficult to deal with
:
•
The negotiations faced many thorny issues.
談判面臨許多棘手的問題。
•
It was a thorny problem that required careful consideration.
這是一個需要仔細考慮的棘手問題。