The characteristically high pitched sound that is emitted from speakers when a loop of interference develops between poorly placed speakers and microphones.
"When we set the mics and turned the system up for micchecks the feedback was screaming"
The phenomenon of a visible and palpable wave of energy resulting from the compression and subsequent decompression of a female ass during "doggy-style" sexual intercourse.
That apple bottom's feedback nearly disrupted my flow, but I still yahtzeed all over her face!