/feed"bak'/ , n.
a. the process of returning part of the output of a circuit, system, or device to the input, either to oppose the input (negative feedback) or to aid the input (positive feedback) .
b. See acoustic feedback .
2. the furnishing of data concerning the operation or output of a machine to an automatic control device or to the machine itself, so that subsequent or ongoing operations of the machine can be altered or corrected.
3. a reaction or response to a particular process or activity: He got very little feedback from his speech.
4. evaluative information derived from such a reaction or response: to study the feedback from an audience survey.
5. Psychol. knowledge of the results of any behavior, considered as influencing or modifying further performance. Cf. biofeedback .
6. Biol. a self-regulatory biological system, as in the synthesis of some hormones, in which the output or response affects the input, either positively or negatively.
[ 1915-20; n. use of v. phrase feed back ]