- The return of a portion of the output of a process or system to the input, especially when used to maintain performance or to control a system or process.
- The portion of the output so returned.
- Sound created when a transducer such as a microphone or electric guitar picks up sound from a speaker connected to an amplifier and regenerates it back through the amplifier.
- The return of information about the result of a process or activity; an evaluative response: asked the students for feedback on the new curriculum.
- The process by which a system, often biological or ecological, is modulated, controlled, or changed by the product, output, or response it produces.