to be dead to the world --------- 昏睡（非正式）

英文释义
(INFORMAL) To be completely asleep or unconscious.

例句
I was so tired after my long trip yesterday that this morning when my alarm went off this morning I was still dead to the world and did not hear it.
昨天，经过长途旅行，我疲惫不堪，以至于今天早上闹钟响时，我根本没听见，仍在昏睡。