What is peters out?

"Peters out" is a phrase used to describe something that loses energy, momentum or comes to an end gradually. It's commonly used to describe a situation or activity that was once active or exciting but is now fizzling out or losing interest, becoming less substantial or diminishing in significance. The term is believed to have originated in the 19th century and was named after a character named Peter who was often depicted as a person who would start with a lot of enthusiasm but eventually lose interest, energy and motivation and end up just staying around doing nothing. Today "petering out" is commonly used in everyday conversations to describe various situations such as friendships, relationships, business ventures, projects, and other activities that eventually lose their original spark and diminish over time.