# folio

> English word · Noun · IPA /ˈfəʊlɪəʊ/ · frequency rank #25,063

## Definitions
1. A leaf of a book or manuscript.
2. A page of a book, that is, one side of a leaf of a book.
3. A page number. The even folios are on the left-hand pages and the odd folios on the right-hand pages.
4. A sheet of paper folded in half.
5. A book made of sheets of paper each folded in half (two leaves or four pages to the sheet); hence, a book of the largest kind, exceeding 30 centimetres in height.
6. A wrapper for loose papers.
7. A page in an account book; sometimes, two opposite pages bearing the same serial number.
8. A protective case with a flap that folds to cover the screen of a mobile device.
9. A leaf containing a certain number of words; hence, a certain number of words in a piece of writing, as in England, in law proceedings 72, and in chancery, 90; in New York, 100 words.

## Etymology
From Middle English folio (“leaf of a book”), borrowed from Medieval Latin foliō, Late Latin foliō, Latin foliō, the ablative singular form of Late Latin folium (“leaf or sheet of paper”), Latin folium (“leaf of a plant”), ultimately from Proto-Indo-European *bʰleh₃- (“bloom, flower”). Doublet of foil and folium, and distantly related to phyllo and phyllon.
Senses 1, 2, 3.1, 5, and 6 relating to a leaf or page are derived from Medieval Latin foliō in references; sense 5 (“page in an account book”) may be derived from Italian foglio (“rectangular sheet of paper”), from Latin folium. Senses 3.2 and 3.3 relating to a paper size are from Italian in foglio or its etymon Latin in foliō.

## Easily confused with
- **foo** (https://plainspell.com/en/vs/folio-vs-foo)
- **folk** (https://plainspell.com/en/vs/folio-vs-folk)
- **FOMO** (https://plainspell.com/en/vs/folio-vs-fomo)
- **folks** (https://plainspell.com/en/vs/folio-vs-folks)
- **folly** (https://plainspell.com/en/vs/folio-vs-folly)
- **forgo** (https://plainspell.com/en/vs/folio-vs-forgo)
- **follow** (https://plainspell.com/en/vs/folio-vs-follow)
- **Folsom** (https://plainspell.com/en/vs/folio-vs-folsom)
- **frolic** (https://plainspell.com/en/vs/folio-vs-frolic)
- **Flo** (https://plainspell.com/en/vs/flo-vs-folio)
- **foi** (https://plainspell.com/en/vs/foi-vs-folio)
- **flip** (https://plainspell.com/en/vs/flip-vs-folio)
- **FOIL** (https://plainspell.com/en/vs/foil-vs-folio)
- **FOIA** (https://plainspell.com/en/vs/foia-vs-folio)
- **foie** (https://plainspell.com/en/vs/foie-vs-folio)
- **Felix** (https://plainspell.com/en/vs/felix-vs-folio)
- **foley** (https://plainspell.com/en/vs/foley-vs-folio)
- **folds** (https://plainspell.com/en/vs/folds-vs-folio)
- **Fabio** (https://plainspell.com/en/vs/fabio-vs-folio)
- **Falco** (https://plainspell.com/en/vs/falco-vs-folio)

## Common misspellings (6)
`ffolio`, `floio`, `foilo`, `follio`, `foloi`, `oflio`

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