[ as-il, -eel ]
/ ˈæs ɪl, -il /

adjective Chemistry.

containing the acyl group.

Nearby words

  1. acyclic,
  2. acyclic compound,
  3. acyclic terpene,
  4. acycloguanosine,
  5. acyclovir,
  6. acyl anhydride,
  7. acyl coa,
  8. acyl coenzyme a,
  9. acyl group,
  10. acyl halide

Origin of acyl

1895–1900; < German: an organic radical derived from an acid; see acid, -yl Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for acyl


/ (ˈeɪsaɪl) /


(modifier) of, denoting, or containing the monovalent group of atoms RCO-, where R is an organic groupacyl group or radical; acyl substitution
an organometallic compound in which a metal atom is directly bound to an acyl group

Word Origin for acyl

C20: from 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

Medicine definitions for acyl


[ ăsəl ]


A organic radical having the general formula RCO, derived from the removal of a hydroxyl group from an organic acid.

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

Science definitions for acyl


[ ăsəl ]

An organic compound containing the group RCO, where R is a halogen. Acyls are formed from organic acids by replacing the hydroxyl group (OH) within the carboxyl group (COOH) with a halogen. For example, acetyl chloride (CH3COCl) is formed by replacing the hydroxyl group of acetic acid (CH3COOH) with a chlorine atom. The names of acyls are formed by replacing the suffix -ic of the acid's name with -yl.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.