Definition of "feedback"

feedback

/ˈfiːdˌbæk/

noun
usually uncountable, plural feedbacks
1. Critical assessment of a process or activity or of their results.
2. (electronics, cybernetics, control theory) The part of an output signal that is looped back into the input to control or modify a system.
  Quotations
  The fact that similar cortical abnormalities can be experimentally induced in monkeys has allowed Michael Merzenich and his colleagues in San Francisco to explore an animal model of focal dystonia, and to demonstrate the abnormal feedback in the sensory loop and the motor misfirings that, once started, grow relentlessly worse.
  2007, Oliver Sacks, Musicophilia: Tales of Music and the Brain
3. (amplification) The high-pitched howling noise heard when there is a loop between a microphone and a speaker.
  Quotations
  A loud feedback screech blasted from a speaker on the wall. It was a hailing signal of some kind.
  2002, John Griesemer, No One Thinks of Greenland, Picador
verb
third-person singular simple present feedbacks, present participle feedbacking, simple past and past participle feedbacked
1. (music) To generate the high-frequency sound by allowing a speaker to cause vibration of the sound generator of a musical instrument connected by an amplifier to the speaker.
2. (transitive) To provide informational feedback to.
3. (transitive) To convey by means of specialized communications channel.