What is the origin of the idiom "vicious circle" and when to use it?
The idiom "vicious circle" is used to refer to a self-perpetuating or self-reinforcing sequence of events or situations where one problem leads to another, and these issues continue to worsen each other in an unending loop. Its origin is related to the idea of a circle with harmful qualities, where each part of the circle reinforces the negative impact of the others.