Definition - What does Lubricate mean?
Lubricate means to apply greasy or oily substance to a part of mechanism or to a machine to make it smooth and reduce the friction so that it can slide or move easily. Mechanics are required to lubricate the parts of an engine constantly so as to replace the old parts with new ones. Oil is the common lubricant used to lubricate various metal surfaces so that they never stick against each other.
Petropedia explains Lubricate
Lubricating is the process of making the metal substances smooth so that they can slide or move easily. The Lubricant can be a liquid like water or oil, solid like molybdenum, gas, and a dispersion of liquid-liquid or a dispersion of solid and liquid. When the fluid lubricants are used, the applied load either gets carried by the liquid that is pumped under pressure between the surfaces or by the pressure generated within the fluid because of its frictional viscous resistance to the motion of the fluid between the surfaces. All machines that have different functions and properties from sewing machines to jumbo jets are required to be lubricated to keep on working properly.