The definition of a breakdown is a mechanical failure, a collapse of a system of authority, a failure of a relationship or interaction, or a collapse of someone's mental health and a descent into permanent or temporary craziness. (noun)
- When your car stops working and will no longer start, this is an example of a breakdown.
- When everyone loses respect for a teacher and stops listening to that teacher at all, this is an example of a breakdown of authority.
- When you tell your spouse to meet you at the restaurant you both like the best and he thinks that you mean a different restaurant and doesn't understand you correctly, this is an example of a breakdown of communication.
- When your boyfriend breaks up with you and you become severely depressed and try to kill yourself and need therapy, this is an example of a breakdown.