1
: operated, moved, or effected by means of water
2
a
: of or relating to hydraulics
hydraulic engineer
b
: of or relating to water or other liquid in motion
hydraulic erosion
3
: operated by the resistance offered or the pressure transmitted when a quantity of liquid (such as water or oil) is forced through a comparatively small orifice or through a tube
hydraulic brakes
4
: hardening or setting under water
hydraulic cement

Did you know?

By means of a hydraulic lift, the driver can lift the bed of a dump truck with the touch of a button. He might also repair the hydraulic steering, the hydraulic brake, or the hydraulic clutch—all of which, like the lift that holds everything up, take advantage of the way liquids act under pressure. Somewhat like a pulley or a lever, a hydraulic system magnifies the effect of moderate pressure exerted over a longer distance into powerful energy for a shorter distance.

Examples of hydraulic in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
In June 1996, the aircraft lost hydraulic pressure at takeoff and had to return. Miami Herald Archives, Miami Herald, 8 Sep. 2026 This caused significant damage to the plane, and all four of its hydraulic lines were severed, directly impacting the aircraft’s controllability. Natalia Senanayake, PEOPLE, 8 Sep. 2026 The software models power production by pairing turbine performance curves with hydraulic head, which measures the potential energy created by water elevation behind a dam. Aman Tripathi, Interesting Engineering, 6 Sep. 2026 Each lockable box has a hydraulic system engineered for smooth daily operation and a roomy interior that provides ample storage for your patio cushions, gardening gear, toys, or outdoor entertaining essentials. Maria Conti, Better Homes & Gardens, 1 Sep. 2026 See All Example Sentences for hydraulic

Word History

Etymology

Latin hydraulicus, from Greek hydraulikos, from hydraulis hydraulic organ, from hydr- + aulos reed instrument — more at alveolus

First Known Use

1661, in the meaning defined at sense 1

Time Traveler
The first known use of hydraulic was in 1661

Browse Nearby Words

Cite this Entry

“Hydraulic.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/hydraulic. Accessed 15 Sep. 2026.

Kids Definition

hydraulic

adjective
1
: operated, moved, or brought about by means of water
2
: of or relating to hydraulics
hydraulic engineer
3
: operated by pressure transmitted when a quantity of liquid is forced through a small hole or through a tube
hydraulic brakes
4
: hardening or setting under water
hydraulic cement
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