To squeeze one's anal passage while in the process of taking a shit of enormous magnitude, resulting in the log being cut into either two or several chunks.

This would occur if the person was scared, starttled or just needed to hurry up and carry on when they get to a suitable location to finish the job.
Women: "Come back to bed baby."
Man: "Silence sex wench!"
Women: "We can do anal.."
Man: *Starts pinching off a loaf*
by Bible Author June 10, 2014
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Take a dump. Poop. Defecate. Drop a load. Cut the crap.
A: "ugh, I think I need to pinch off a loaf"

B: "what?! you need to chipoffolo?"

A: "NO DUDE!! I said: PINCH OFF A LOAF!"

B: "Oh (pause) what the hell?"
by Metso July 11, 2008
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