# lunacy

> English word · Noun · IPA /ˈluː.nə.si/ · frequency rank #32,485

## Definitions
1. The state of being mad, insanity
2. The state of being mad, insanity
3. Something deeply misguided.

## Etymology
From lunatic + -cy.

## Easily confused with
- **lunch** (https://plainspell.com/en/vs/lunacy-vs-lunch)
- **lunar** (https://plainspell.com/en/vs/lunacy-vs-lunar)
- **Lundy** (https://plainspell.com/en/vs/lunacy-vs-lundy)
- **Lucy** (https://plainspell.com/en/vs/lucy-vs-lunacy)
- **luna** (https://plainspell.com/en/vs/luna-vs-lunacy)
- **lacy** (https://plainspell.com/en/vs/lacy-vs-lunacy)
- **legacy** (https://plainspell.com/en/vs/legacy-vs-lunacy)

## Common misspellings (9)
`llunacy`, `lnuacy`, `luancy`, `lunaccy`, `lunacyy`, `lunayc`, `luncay`, `lunnacy`, `ulnacy`

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