hydraulic

adjective

hy·​drau·​lic hī-ˈdrȯ-lik 

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

hydraulically

hī-ˈdrȯ-li-k(ə-)lē 

adverb

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

Jack Cress, a helicopter accident investigation instructor at USC’s Aviation Safety and Security Program, told the newspaper that the alarm sounded off because of possible engine failure or an issue with the hydraulic system. — David Chiu, PEOPLE, 17 Sep. 2026

Electronic actuators control the brake calipers instead of hydraulic lines carrying brake fluid. — Kurt Knutsson, FOXNews.com, 15 Sep. 2026

Using hydraulic modeling, MMSD determined that about 400 properties would have faced an elevated risk of basement backups even if the pipe had been open during April’s weeklong storms, which brought up to 9 inches of rain. — Caitlin Looby, jsonline.com, 10 Sep. 2026

In June 1996, the aircraft lost hydraulic pressure at takeoff and had to return. — Miami Herald Archives, Miami Herald, 8 Sep. 2026

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

Phrases Containing hydraulic

• hydraulic fracturing

Rhymes for hydraulic

• bucolic
• carbolic
• embolic
• glycolic
• phenolic
• podzolic
• symbolic
• systolic
• alcoholic
• anabolic
• apostolic
• catabolic

Kids Definition

hydraulic

adjective

hy·​drau·​lic hī-ˈdrȯ-lik 

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

hydraulically

-ˈdrȯ-li-k(ə-)lē 

adverb