Main Entry: feed·back

Pronunciation: \ˈfēd-ˌbak\

Function: noun

Date: 1919

1 : the return to the input of a part of the output of a machine, system, or process (as for producing changes in an electronic circuit that improve performance or in an automatic control device that provide self-corrective action)
2 a : the partial reversion of the effects of a process to its source or to a preceding stage b : the transmission of evaluative or corrective information about an action, event, or process to the original or controlling source; also : the information so transmitted
3 : a rumbling, whining, or whistling sound resulting from an amplified or broadcast signal (as music or speech) that has been returned as input and retransmitted