His entire future was becoming like a river hurtling toward a chasm — the violent nexus beyond which all was fog and clouds.
DUST CHASM: any deep crevasse or depression on the desert of Arrakis that has been filled with dust not apparently different from the surrounding surface; a deadly trap because human or animal will sink in it and smother.
There are no more uses of "chasm" in the book.
Show samples from other sources
You can’t leap a twenty-foot chasm with two 10-foot jumps.