必ひつ要よう不ふ可か欠けつ

na-adjective, noun which may take the genitive case particle 'no'

absolutely essential; indispensable; vital

Stronger than 必要 alone; emphasizes that something is not just needed but cannot be done without. Often used in formal or explanatory contexts.

• 水みずは生せい命めいにとって必ひつ要よう不ふ可か欠けつだ。

  Water is absolutely essential for life.

• この書しょ類るいは申しん請せいに必ひつ要よう不ふ可か欠けつです。

  This document is indispensable for the application.