ethylene glycol

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A colorless sweet-tasting viscous diol, C₂H₆O₂, used as an antifreeze in cooling and heating systems.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun organic chemistry An organic compound, HO-CH2-CH2-OH, and the chemical structure at right. It is a clear, colorless liquid under normal conditions, and is widely used as a vehicle engine coolant due to its anti-freeze properties.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a sweet but poisonous syrupy liquid used as an antifreeze and solvent