ethane

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

• noun A colorless, odorless gaseous alkane, C₂H₆, that occurs as a constituent of natural gas and is used as a fuel and a refrigerant.

from The Century Dictionary.

• noun A colorless, odorless gas, CH₃CH₃, found in illuminating gas and in crude petroleum, and prepared by the action of hydrogen on ethylene, acetylene, or ethyl iodide, and by the action of water on zinc ethyl. It boils at —93° C. Also called methylmethane, dimethyl, and ethyl hydrid.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Chem.) A gaseous hydrocarbon, C2H6, forming a constituent of ordinary illuminating gas. It is the second member of the paraffin series, and its most important derivatives are common alcohol (ethyl alcohol), acetaldehyde, ether, and acetic acid. Called also dimethyl.

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

• noun organic chemistry (uncountable) An aliphatic hydrocarbon, C2H6, gaseous at normal temperatures and pressures, being a constituent of natural gas.
• noun organic chemistry (countable) The same compound, subjected to modification by replacing one or more of the hydrogen atoms with other radicals.

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

• noun a colorless odorless alkane gas used as fuel