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.
Enhancing regional transport This vessel is also a major milestone in marine construction technology as the first pile driver equipped with a closed-loop main cylinder hydraulic system. — Mrigakshi Dixit, Interesting Engineering, 29 Sep. 2026 There are hydraulic disc brakes at both ends for stopping power. — New Atlas, 28 Sep. 2026 Its wind program trains the technicians who climb inside these increasingly large and sophisticated machines to maintain the electrical, hydraulic, and mechanical systems that keep them turning. — Harry Bruinius, Christian Science Monitor, 28 Sep. 2026 Antonelli's day was disrupted by a hydraulic failure which left his car smoking at the side of the track in the first session. — ABC News, 24 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 5 Oct. 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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