# have bats in one's belfry

> English word · Verb

## Definitions
1. To be crazy or eccentric.

## Etymology
1899, from tendency of bats to fly around erratically, with “belfry” indicating “head, mind”.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-09-03.
Canonical page: https://plainspell.com/en/word/have-bats-in-one-s-belfry