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.
It’s paired with 270-mm front and 240-mm rear hydraulic disc brakes. New Atlas, 27 July 2026 The device converts the squeeze into hydraulic pressure and displays peak isometric force on a dial in kilograms or pounds. Samantha Agate, Sacbee.com, 23 July 2026 Venezuelan rescuers often relied on sledgehammers, pickaxes and shovels because hydraulic rescue equipment and heavy machinery were unavailable. Antonio María Delgado, Miami Herald, 23 July 2026 The device features an adjustable metal handle connected to a hydraulic fluid system. Samantha Agate, Fort Worth Star-Telegram, 23 July 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 3 Aug. 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

More from Merriam-Webster on hydraulic

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

More from Merriam-Webster