# iff

> English word · Conjunction · IPA /ɪf ən(d)ˈəʊn.li ɪf/ · frequency rank #45,443

## Definitions
1. Abbreviation of if and only if.

## Easily confused with
- **in** (https://plainspell.com/en/vs/iff-vs-in)
- **is** (https://plainspell.com/en/vs/iff-vs-is)
- **it** (https://plainspell.com/en/vs/iff-vs-it)
- **II** (https://plainspell.com/en/vs/iff-vs-ii)
- **IV** (https://plainspell.com/en/vs/iff-vs-iv)
- **IP** (https://plainspell.com/en/vs/iff-vs-ip)
- **IQ** (https://plainspell.com/en/vs/iff-vs-iq)
- **IG** (https://plainspell.com/en/vs/iff-vs-ig)
- **io** (https://plainspell.com/en/vs/iff-vs-io)
- **IK** (https://plainspell.com/en/vs/iff-vs-ik)
- **iz** (https://plainspell.com/en/vs/iff-vs-iz)
- **IH** (https://plainspell.com/en/vs/iff-vs-ih)
- **IJ** (https://plainspell.com/en/vs/iff-vs-ij)
- **its** (https://plainspell.com/en/vs/iff-vs-its)
- **inc** (https://plainspell.com/en/vs/iff-vs-inc)
- **ill** (https://plainspell.com/en/vs/iff-vs-ill)
- **ion** (https://plainspell.com/en/vs/iff-vs-ion)
- **iOS** (https://plainspell.com/en/vs/iff-vs-ios)
- **ink** (https://plainspell.com/en/vs/iff-vs-ink)
- **inn** (https://plainspell.com/en/vs/iff-vs-inn)

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