expression, noun-modifying (irregular)
urgent; requiring immediate action
Used to describe situations, matters, or tasks that demand a quick response or cannot be postponed. Often modifies nouns like 問題, 用件, or 事態.
This is an urgent problem.
I called you about an urgent matter.
A set phrase combining 急 (urgency) with を要する (to require). The structure follows classical Chinese-influenced patterns common in formal Japanese.