hydraulic press

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A machine in which a large force is exerted on the larger of two pistons in a pair of hydraulically coupled cylinders by means of a relatively small force applied to the smaller piston.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun press in which a force applied by a piston to a small area is transmitted through water to another piston having a large area