Definition of hydraulic
1
: operated, moved, or effected by means of water
2a
: 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
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Merriam-Webster unabridged
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Time Traveler for hydraulic
The first known use of hydraulic was in 1661
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