In electronics, a device that takes a small electric signal and converts it into a large one. Amplifiers are used in stereo systems, electric guitars, and loudspeakers.
Main Entry: am·pli·fi·er Pronunciation: 'am-pl&-"fI(&)r Function: noun : one that amplifies; specifically: anelectronic device (as in a computer or sound-reproducing system) for amplifying voltage, current, or power