/ haɪˈdrɔːlɪk; NAmE ; BrE also -ˈdrɒl-/ adjective [ usually before noun ]
1.
( of water, oil, etc. ) moved through pipes, etc. under pressure :
hydraulic fluid
2.
( of a piece of machinery ) operated by liquid moving under pressure :
hydraulic brakes
3.
connected with hydraulic systems :
hydraulic engineering
► hy·draul·ic·al·ly / -kli; NAmE / adverb :
hydraulically operated doors
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WORD ORIGIN
early 17th cent.: via Latin from Greek hudraulikos , from hudro- water + aulos pipe.