# theta wave

> English word · Noun

## Definitions
1. A type of electrical activity in the brain; a brain wave with a frequency of 4-8 hertz.

## Etymology
From theta + wave.

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