A: Dan forgot his map?
A: Dan 忘了带地图了吗?
B: Yep! And he's bound to lose his way.
B: 是的!他铁定要迷路了.
"bound to" 是必定的意思. "你死定了!"就可以说 "You're bound to die.".
想说谁死定了, 最简单的说法是 you are doomed!