Cease to function (9)
(Other definitions for breakdown that I've seen before include "Collapse - analysis" , "Detailed analysis" , "Stop working" , "Analysis < of separation" , "making you burst into tears?" .)
(Other definitions for break down that I've seen before include "Fall through" , "Mechanical failure" , "Collapse - analysis" , "Cease functioning" , "Analyse - total failure" .)