amplifier

n. device which amplifies or increases (power, current, etc.)

Generally, an amplifier is any device that will use a small amount of energy and convert it to a larger amount of energy. In popular use, the term today usually refers to an electronic amplifier, often as in audio applications. The relationship of the input to the output of an amplifier — usually expressed as a function of the input frequency — is called the transfer function of the amplifier, and the magnitude of the transfer function is termed the gain.
See more at Wikipedia.org...

Noun
1. electronic equipment that increases strength of signals passing through it
(hypernym) electronic equipment
(hyponym) audio amplifier
(part-holonym) radio receiver, receiving set, radio set, radio, tuner, wireless
(derivation) magnify, amplify

n. amplifier, device which amplifies or increases (power, current, etc.)

v. amplify; exaggerate, magnify