fossil fuel

/ˌfɑsəl ˌˈfju(ə)l/

/ˈfɒsəl fjul/

Other forms: fossil fuels

A source of energy that comes from ancient, decomposed organisms is a fossil fuel. Natural gas and coal are both examples of fossil fuels.

Today's fossil fuels began forming millions of years ago, before dinosaurs lived on the earth. Over time, these plants and other organisms died, decomposed, and sank to the bottom of the ocean. Over time, heat and pressure eventually turned them into coal, oil, and gas. While the world depends on fossil fuels to power vehicles and produce electricity, they are ultimately very hard on the planet, creating enormous amounts of carbon dioxide.

Definitions of fossil fuel

1. noun

   fuel consisting of the remains of organisms preserved in rocks in the earth's crust with high carbon and hydrogen content
   types:

   coal

   fossil fuel consisting of carbonized vegetable matter deposited in the Carboniferous period

   gas, natural gas

   a fossil fuel in the gaseous state; used for cooking and heating homes

   crude, crude oil, fossil oil, oil, petroleum, rock oil

   a dark oil consisting mainly of hydrocarbons

   anthracite, anthracite coal, hard coal

   a hard natural coal that burns slowly and gives intense heat

   bituminous coal, soft coal

   rich in tarry hydrocarbons; burns readily with a smoky yellow flame

   brown coal, lignite, wood coal

   intermediate between peat and bituminous coal

   steam coal

   coal suitable for use under steam boilers

   resid, residual oil

   oil products that remain after petroleum has been distilled

   type of:

   fuel

   a substance that can be consumed to produce energy