noun
: a fluid usually of low viscosity (as oil or glycerol but seldom water) used in a hydraulically operated mechanism
hydraulic fluid in a brake cylinder
noun
: a fluid usually of low viscosity (as oil or glycerol but seldom water) used in a hydraulically operated mechanism
hydraulic fluid in a brake cylinder
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012