# deep sleep

> English word · Noun

## Definitions
1. Used other than figuratively or idiomatically: see deep, sleep.
2. stage 3 of non-rapid eye movement sleep
3. Artificially induced hibernation in humans for the purpose of long distance space travel.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/deep-sleep