barrier; obstacle; difficulty; hurdle; deadlock
彼は難関大学に合格した。
He passed the entrance exam for a highly competitive university.
我が社は今、開発の難関に直面している。
Our company is currently facing a major hurdle in development.
規制当局の難関をクリアし、新薬がついに承認された。
After clearing the regulatory hurdles, the new drug was finally approved.