Definition of a Gear

Definition of a Gear Points : Definition of a Gear, Gear and Pinion Definition The term gear may be used in engineering practice for almost any kind of mechanism, but it refers especially to a toothed wheel, in other words a gear is a Wheel on which teeth have been formed. Or
By definition a gear is a form of a disc or wheel having teeth around its periphery to provide a positive drive by the engagement of these teeth with similar teeth on another gear or rack. In such an arrangement there can be no slip as with a belt drive. Or:

A gear is a toothed wheel which when meshed with other gear transmits motion and power from one shaft to other shaft. The teeth are formed partly above and partly below the pitch surface. The gears transmit Power without any slip while in belts some slip occurs.

Gear and Pinion Two gears in mesh are called a pair of gears. The larger of the two is referred to as the gear, while the smaller one is called the pinion. Either could be a driver and the driven member.