A lubricant is a substance introduced to reduce friction between
surfaces in mutual contact, which
ultimately reduces the heat generated when the surfaces move. It
may also have the function of transmitting forces, transporting foreign
particles, or heating or cooling the
surfaces. The property of reducing
friction is known as lubricity.
In addition to industrial applications,
lubricants are used for many other
purposes. Other uses include cooking (oils and fats in use in frying
pans, in baking to prevent food
sticking), bio-medical applications
on humans (e.g. lubricants for artificial joints), ultrasound examination,
medical examinations, and the use
of personal lubricant for sexual purposes.