fateful; life-and-death; mortal; of vital importance; vital (ly) ? 特命你今夜十一時，按原訂計劃行動，～，勿誤。(黎汝清《海島女民兵》276) I order you to take action as pre arranged. Time: 23:00 hours tonight. Your obe dience is a life-and-death matter.
生死攸關(guān)shēnɡ sǐ yōu ɡuān
攸：所。比喻事態(tài)嚴(yán)重；也形容關(guān)系到別人的生死存亡問題。a matter of life and health, of vital importance, at stake