Formal term for matters of great importance or urgency. Often used in official or serious contexts.
This is an urgent matter.
Tackle a vital task.
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Standard kanji form. Used in formal and written contexts.
Kana spelling is acceptable, especially in less formal writing or when the kanji are considered difficult.
Compound of 緊 (urgent, tense) and 要 (essential, need). The combination conveys something both urgent and essential.