thorny
US /ˈθɔːr.ni/
UK /ˈθɔːr.ni/

1.
2.
espinoso, complicado, difícil
causing difficulties or disagreements; complex and difficult to deal with
:
•
The negotiations faced many thorny issues.
Las negociaciones enfrentaron muchos problemas espinosos.
•
It was a thorny problem that required careful consideration.
Era un problema espinoso que requería una cuidadosa consideración.