hydraulic

American  

[hahy-draw-lik, -drol-ik] / haɪˈdrɔ lɪk, -ˈdrɒl ɪk /

adjective

1. operated by, moved by, or employing water or other liquids in motion.

2. operated by the pressure created by forcing water, oil, or another liquid through a comparatively narrow pipe or orifice.

3. of or relating to water or other liquids in motion.

4. of or relating to hydraulics.

5. hardening under water, as a cement.

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hydraulic British  

/ haɪˈdrɒlɪk /

adjective

1. operated by pressure transmitted through a pipe by a liquid, such as water or oil

2. of, concerned with, or employing liquids in motion

3. of or concerned with hydraulics

4. hardening under water

   hydraulic cement

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hydraulic Scientific  

/ hī-drô′lĭk /

1. Operated by the pressure of water or other liquids. Hydraulic systems, such as hydraulic brakes, allow mechanical force to be transferred along curved paths (through pipes or tubes) that would be difficult for solid mechanisms, such as levers or cables, to negotiate efficiently.

2. Relating to hydraulics.

3. Capable of hardening under water, as cement.

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hydraulic Cultural  

1. A descriptive term for a system operated or moved by a fluid. The hydraulic jack, in which force is transmitted from a handle by means of a heavy oil, is probably the most familiar hydraulic device.

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Other Word Forms

• nonhydraulic
  adjective
• unhydraulic
  adjective
• hydraulically
  adverb

Etymology

Origin of hydraulic

1620–30; < Latin hydraulicus < Greek hydraulikós of a water organ. See hydraulus, -ic

Explanation

The adjective hydraulic refers to a process using pressurized water or other fluid to generate great mechanical power, without the wear and tear of gears or levers. Hydraulic systems are popular for use in heavy-duty machinery. It might seem odd that the original Greek word hydraulikós from which hydraulic comes referred to water (hydra) and also to a musical instrument made from a hollow tube (aulos). You might ask, "What's a musical instrument got to do with hydraulics?" Well, you can see the connection when you know that something that's hydraulic means it is operated through the pressure of water or liquid through a pipe or hose, easily generating great force (instead of music).

Example Sentences

Think of it as the aircraft's emergency windmill: if both engines fail, or the plane loses normal electrical or hydraulic power, a small turbine drops into the airstream and generates backup power.

From BBC • Jun. 15, 2026

Stellantis said an internal investigation identified a connection issue in the wiring of the cars’ electric hydraulic power steering pump.

From The Wall Street Journal • Jun. 12, 2026

Fort is just one of several new businesses - from high-tech hydraulic homes to grass-clearing goats - to emerge as wildfires continue to worsen.

From BBC • Jun. 3, 2026

The passageway is accessed using a “sophisticated hydraulic lift” and extends from Otay Mesa, underneath the U.S.-Mexico border and into Tijuana.

From Los Angeles Times • Jun. 2, 2026

It has powerful hydraulic pistons hooked to rudder, ailerons, and elevator, which means that if you move your hand on the stick or your feet on the rudders ever so slightly, the airplane reacts immediately.

From "Flying to the Moon: An Astronaut's Story" by Michael Collins