ぼつらく没落botsuraku
1.

The process by which something that was once prosperous, such as a nation or noble class, fades into decline and loses its former glory or status.

2.

The event where a stronghold or territory succumbs to defeat, resulting in its loss of power or control.

3.

A derogatory term used to insult someone, implying their descent into a pitiful state or disgrace.

Example:

商売でそんな失敗をしたらどんな会社でも没落する。