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.
Example: "The show ended with a riot of feedbacking guitars."
To provide informational feedback to.
Example: "His employees feedbacked him a lot more than he wanted."
To convey by means of specialized communications channel.
Example: "Customers feedbacked their complaints and some praise."