An unspoken, dual-definition phrase invented by two scholars one night. After edibles.
It can mean the following. Either:
1) A person possessing a large member/dong/phallus/dick. Like "packing heat"
2) Holding in a shit real bad to the point you feel it unfurl upon exiting.
Can mean either in the following example:
Person 1: "Where's Jason gone?"
Person 2: "He's holding rope, had to go sort it out"