寝させて

let me sleep, let someone sleep

→ 寝る
sleep, go to bed + させ causative (make/let someone do) + Te-form (conjunctive)
verb Rare #41,614
let me sleep, let someone sleep Often used as a request meaning “let me sleep”; can also mean “make someone sleep” depending on context.
JA: もう少し寝させて。
EN: Let me sleep a little longer.
Conjugation of 寝る

もう少し寝させて

Let me sleep a little longer.

もうちょっと寝させて

Let me sleep a little longer.

お願い寝させて

Please let me sleep.

ここで寝させて

Let me sleep here.

— 帰ってきたヒトラー (2015)