# 4to

> English word · Noun · frequency rank #72,052

## Definitions
1. Abbreviation of quarto, a paper size.
2. Abbreviation of quarto, a corresponding book size.

## Etymology
From Latin quārtō, ablative case singular of quārtus (“fourth”).

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/4to