Dead Drunk, Completely Drunk
noun, verbal noun
If you're mud drunk, you're so drunk you're rolling around on the ground. You are dead drunk.
でいすい
This is a jukugo word that uses the on'yomi readings of the kanji. You haven't seen the on'yomi reading for 泥 yet (でい), so here's a mnemonic to help you out: You'll probably get dead drunk if you start drinking in the middle of the day (でい). Just try to wait until the day is over, like maybe after work, you know?
完璧に泥酔していて、方向感覚を失っていました。
I was completely drunk and lost my sense of direction.