We’ll skip the jokes, and give you two music/audio definitions for this term:
1. Short for “potentiometer.”
2. To encase, saturate, or seal the coils of a guitar or bass pickup, often in wax, to prevent them from squealing with feedback under high volume conditions.
Note: we’re not talking about “musical” feedback, we’re talking about obnoxious coil feedback similar to what happens when you point a microphone into a speaker.