Definition - What does Underclocking mean?
Underclocking refers to alterations of the timing of a synchronous circuit in order to lower a device's energy needs. Deliberate underclocking involves limiting a processor's speed, which may affect the speed of operations, but may or may not make a device noticeably less able, depending on other hardware and desired use.
Techopedia explains Underclocking
Many computers and other devices allow for underclocking. Manufacturers add underclocking options for many reasons. Underclocking can help with excessive heat buildup, because lower performance will not generate as much heat inside the device. It can also lower the amount of energy needed to run the device. Laptop computers and other battery-operated devices often have underclocking settings, so that batteries can last longer without being charged.
In addition to providing underclocking features, manufacturers can choose to limit the capability of a machine in order to make it more efficient. Reduced instruction set computer (RISC) models can help makers build devices that work on less power.