[ byoo-til, byoot-l ]
/ ˈbyu tɪl, ˈbyut l /

adjective Chemistry.

containing a butyl group.

Origin of butyl

First recorded in 1865–70; but(yric) + -yl

Definition for butyl (2 of 2)

[ byoo-til, byoot-l ]
/ ˈbyu tɪl, ˈbyut l /


a brand of synthetic rubber prepared by polymerization of butylene containing little butadiene, particularly useful for inner tubes of automobile tires because of its leakproof qualities.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Examples from the Web for butyl

  • The stuff smelled like a mixture of spirits of ammonia and butyl mercaptan, but it did the job.

    The Highest Treason|Randall Garrett
  • There are also higher alcohols, that is, those having more complex chemical formulas, such as butyl alcohol.

    Encyclopedia of Diet|Eugene Christian
  • It has the characteristic odour of the flowers, and consists of a mixture of butyl and amyl angelates and valerates.

  • "And butyl mercaptan; I'm quite aware of that," said the Doctor quickly, to continue the tradition of omniscience.

    Skippy Bedelle|Owen Johnson

British Dictionary definitions for butyl

/ (ˈbjuːˌtaɪl, -tɪl) /


(modifier) of, consisting of, or containing any of four isomeric forms of the group C 4 H 9butyl rubber

Word Origin for butyl

C19: from but (yric acid) + -yl
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for butyl

[ byōōtl ]


A hydrocarbon radical, C4H9.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for butyl

[ byōōtl ]

The radical C4H9, derived from butane.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.