hydraulic

Concise Oxford English Dictionary © 2008 Oxford University Press:
hydraulic /hʌɪˈdrɔːlɪk, hʌɪˈdrɒlɪk/

▶adjective

• 1 denoting or relating to a liquid moving in a confined space under pressure.

• 2 relating to the science of hydraulics.

• 3 (of cement) hardening under water.

– derivatives
hydraulically adverb.

– origin C17: via L. from Gk hudraulikos, from hudro- ‘water’ + aulos ‘pipe’.