# sleeplessness

> English word · Noun · frequency rank #67,051

## Definitions
1. Lack of sleep; the property of being sleepless; the inability to sleep, insomnia.

## Etymology
From sleepless + -ness.

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