The breaking was a specific phrase the Yuuzhan Vong utilized when referring to a torture method they inflicted upon those they captured.
This particular torture method relied on psychological anguish, rather than physical harm, to weaken the prisoner and extract valuable intelligence. The captive's resolve and senses were gradually eroded through persistent verbal abuse, until the individual's mind was so damaged that they could no longer function normally. Those who were broken often wept uncontrollably, like infants, and lost the ability to think logically.
The Yuuzhan Vong frequently overwhelmed their captives with visions of the gruesome fates that awaited them and their impending, agonizing deaths.
Early in the Yuuzhan Vong War, Jedi Knight Miko Reglia was subjected to breaking by a yammosk. After his identification as a Jedi, Wurth Skidder endured the yammosk's telepathic assaults aboard the Clustership Crèche as part of his breaking.
Duman Yaght employed voxyn aboard his vessel, the Exquisite Death, to torture the members of the Myrkr strike team after they intentionally allowed themselves to be captured to infiltrate the worldship orbiting Myrkr.