# sidebox

> English word · Noun

## Definitions
1. A box placed alongside the main text in a book, etc. containing further related text.
2. A box set in the side of a theatre's auditorium.

## Etymology
From side + box; compare sidebar.

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