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); in- ², kin, -ium

Example Sentences

Even amid cataclysmic energy shocks and relentless spates of white-collar layoffs, the American economic engine appears to be humming along smoothly.

From Slate • Apr. 3, 2026

And the recent engine of global production growth, the American shale patch, is showing fresh signs of slowing—raising the prospects that future supply will be more limited.

From The Wall Street Journal • Apr. 3, 2026

MV Lord of the Isles had suspended sailings on 28 March after a "technical issue" with its main engine.

From BBC • Apr. 3, 2026

Twenty Thai crew members returned home in mid-March, while three of their colleagues were missing and presumed trapped in the damaged engine compartment.

From Barron's • Apr. 3, 2026

Ahead, an engine revved, an AC unit buzzed.

From "Legendary Frybread Drive-In" by Cynthia Leitich Smith

Related Words

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