hydraulic fluid

noun

1. a fluid, usually of low viscosity, as oil, used in a hydraulic system.

Word History and Origins

Origin of hydraulic fluid¹

First recorded in 1940–45

Example Sentences

A motorized pump moves hydraulic fluid in and out of the chambers, and that fluid moves the membrane to let blood flow through.

From Singularity Hub 

The artificial heart has a chamber for hydraulic fluid and one for blood, separated by a membrane.

From Singularity Hub 

This would produce changes in the pressure of the hydraulic fluid by affecting the kinetic energy of the fluid's atoms.

From Project Gutenberg