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.
Issues documented included chemical burns and hydraulic fluid that leaked from a ride into someone’s eye, dislocated joints, concussions and broken bones. — Blake Ellis, CNN Money, 15 Oct. 2026 In 2024, the company promoted its thin new iPad Pro by crushing musical instruments, cameras, and other creative tools beneath a hydraulic press, prompting a backlash and an apology. — Tatiana Sataua, Fortune, 15 Oct. 2026 Called Neo1, the 13-foot-class robot combines hydraulic actuators with electric drives to deliver substantial lifting force and precise movement. — Aamir Khollam, Interesting Engineering, 14 Oct. 2026 That was the case with hydraulic mining in the West, which involved aiming a torrent of water under high pressure to blast away soil and boulders to expose the underlying gold veins. — Business Columnist, Los Angeles Times, 13 Oct. 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 20 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
Love words? Need even more definitions?

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