Translation

重大な / 重要な / 影響の大きい

Meaning

Consequential means important because it has serious results or effects. It is more formal than important and often points to decisions, events, changes, or risks with real consequences.

Examples

• その判決は会社にとって重大でした。
  The ruling was consequential for the company.
• これは今年最も重要な政策変更かもしれません。
  This may be the year's most consequential policy change.