Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio.
a gas, largely methane, formed in coal mines, which is explosive when mixed with air
Used by arrangement with John Wiley & Sons, Inc.
The American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
- A combustible gas, chiefly methane, occurring naturally in mines from the decomposition of coal.
- The explosive mixture of firedamp and air.