break down
verb
Definitions
To fail, to cease to function.
Example: I am afraid my computer will break down if I try to run it at too high a speed.
To render or to become unstable due to stress, to collapse physically or mentally.
Example: She is back to work now, after she broke down the other day.
To render or to become weak and ineffective.
Example: His authority and influence over his coordinates broke down gradually.
To (cause to) decay, to decompose.
Example: Leaves and grass will break down into compost faster if you keep them moist.