Translation

予後を予測する / 経過を見通す / 見込みを立てる

Meaning

Prognose means to predict the likely course or outcome of a disease or situation. It is much less common than diagnose and often sounds medical or technical. The trap is using diagnose when you mean future outlook.

Examples

• 医師は検査結果をもとに回復の見通しを立てました。
  The doctor prognosed the patient's recovery based on the test results.
• 日常会話では prognose より predict や estimate の方が自然です。
  In everyday conversation, predict or estimate is more natural than prognose.