natural gas: Meaning and Definition of

nat'ural gas'

Pronunciation: [key]
  1. a combustible mixture of gaseous hydrocarbons that accumulates in porous sedimentary rocks, esp. those yielding petroleum, consisting usually of over 80 percent methane together with minor amounts of ethane, propane, butane, nitrogen, and, sometimes, helium: used as a fuel and to make carbon black, acetylene, and synthesis gas.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.