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.

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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

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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

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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); see 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

Given Apple’s iPhone remains its profit engine, the biggest concern is if AI-powered hardware devices finally make inroads against smartphones.

From Barron's • Apr. 21, 2026

But EV sales — despite being the cash engine fueling Tesla’s massive ambitions — have become less of a concern for investors, who are now preoccupied by Tesla’s robotaxi service.

From MarketWatch • Apr. 21, 2026

Blue Origin's chief executive Dave Limp said the failure was caused by a lack of "sufficient thrust" in an engine.

From BBC • Apr. 20, 2026

In consumer debt, the private-credit engine is powering a variety of companies including financial-technology firms to turn out more and more loans.

From The Wall Street Journal • Apr. 19, 2026

So the engineer will open something they call a “blow-off valve” to release some of the steam and ease the pressure on the engine.

From "The (Mostly) True Story of Cleopatra's Needle" by Dan Gutman

Related Words

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