# butyl

> English word · Noun · IPA /ˈbjuːtɪl/ · frequency rank #52,833

## Definitions
1. Any of four isomeric univalent hydrocarbon radicals, C₄H₉, formally derived from butane by the loss of a hydrogen atom.
2. A synthetic rubber made by the polymerization of isobutylene.

## Etymology
PIE word
 *gʷṓws
From but- + -yl.

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