noun Chemistry.
  1. a volatile, colorless, water-soluble liquid, C2H4O, having a pungent, fruitlike odor: used chiefly in the silvering of mirrors and in organic synthesis.

Origin of acetaldehyde

First recorded in 1875–80; acet- + aldehyde
Also called ethanal. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for acetaldehyde

Historical Examples of acetaldehyde

  • Acetaldehyde is not of much importance in itself, but is useful as a transition.

    Creative Chemistry

    Edwin E. Slosson

  • This is in harmony with the fact that the polymerisation of acetaldehyde is accompanied by evolution of heat.

  • For this reason it is possible to determine the freezing point curves of acetaldehyde and paraldehyde.

  • Starting in the one case with fused paraldehyde, and in the other case with acetaldehyde, the same freezing point, viz.

  • The decomposition of pyruvic acid into acetaldehyde and carbon dioxide has already been fully discussed (Chapter VI).

British Dictionary definitions for acetaldehyde


  1. a colourless volatile pungent liquid, miscible with water, used in the manufacture of organic compounds and as a solvent and reducing agent. Formula: CH 3 CHOSystematic name: ethanal
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

acetaldehyde in Medicine


  1. A colorless, flammable liquid formed during ethanol metabolism and yeast fermentation of organic compounds and used to manufacture acetic acid and drugs.aldehyde ethaldehyde
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

acetaldehyde in Science


  1. A colorless, flammable liquid, used to manufacture acetic acid, perfumes, and drugs. Chemical formula: C2H4O.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.