engine

American  

[en-juhn] / ˈɛn dʒən /

noun

1. a machine for converting thermal energy into mechanical energy or power to produce force and motion.

2. a railroad locomotive.

3. a fire engine.

4. Computers. a piece or collection of software that drives a later process (used in combination, as in ).

5. any mechanical contrivance.

6. a machine or instrument used in warfare, as a battering ram, catapult, or piece of artillery.

7. a means by which something is achieved, accomplished, or furthered.

   Trade is an engine of growth that creates jobs, reduces poverty, and increases economic opportunity.

8. Obsolete. an instrument of torture, especially the rack.

---

engine British  

/ ˈɛndʒɪn /

noun

1. any machine designed to convert energy, esp heat energy, into mechanical work

   a steam engine

   a petrol engine

2. 1. a railway locomotive

   2. ( as modifier )

      the engine cab

3. military any of various pieces of equipment formerly used in warfare, such as a battering ram or gun

4. obsolete any instrument or device

   engines of torture

---

engine Scientific  

/ ĕn′jĭn /

1. A machine that turns energy into mechanical force or motion, especially one that gets its energy from a source of heat, such as the burning of a fuel. The efficiency of an engine is the ratio between the kinetic energy produced by the machine and the energy needed to produce it.

2. See more at internal-combustion engine steam engine See also motor

---

Other Word Forms

• engineless adjective
• multiengine noun

Etymology

Origin of engine

First recorded in 1250–1300; Middle English engin, from Anglo-French, Old French engign, enging, from Latin ingenium “nature, innate quality, mental power, clever invention,” equivalent to in- “in” + -genium (equivalent to gen- “begetting” + -ium noun suffix); in- ², kin, -ium

Explanation

An engine is a machine that burns fuel to make something move. The engine in a car is the motor that makes it go. Engines power vehicles including cars, trains, airplanes, and boats. While these engines tend to be powered by fuel that's burned, other engines get their power from electricity, which they convert to mechanical energy — fans, power tools, and small appliances all commonly have electric engines. Figuratively, you can also use the word engine to mean "something that's used to bring about a specific result." In your state, for example, tourism might be the main engine of job growth.

Example Sentences

Then with a burn of their spacecraft's main engine, they said goodbye and began their quarter of a million mile journey to the Moon.

From BBC • Apr. 11, 2026

Scalia said his goal was to “remove barriers to the greatest engine of economic prosperity the world has ever known: the innovation, initiative, and drive of the American people.”

From Los Angeles Times • Apr. 10, 2026

With the engine in the rear of the vehicle, the Tucker sedans were among the first cars to feature what’s now called a “frunk”—short for “front trunk”—that is common in today’s electric vehicles.

From The Wall Street Journal • Apr. 8, 2026

Shares of other engine suppliers were higher in overseas trading.

From Barron's • Apr. 8, 2026

The quad was loud, but he couldn’t hear the roar of the engine above the wind.

From "Storm Runners" by Roland Smith

Related Words

• appliance
• diesel
• generator
• instrument
• motor
• power plant
• tool
• transformer
• turbine
• weapon