# harmonica bug

> English word · Noun

## Definitions
1. An electronic eavesdropping device (bug) that attaches to a landline telephone and is activated or deactivated by a specific tone. When activated, it prevents the telephone from ringing but activates its microphone to transmit to another telephone at a remote location.

## Etymology
From harmonica for the tone that activates or deactivates the device, and bug (an electronic eavesdropping device).

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