تعریف و معنای "[lose] steam"

What is the origin of the idiom "lose steam" and when to use it?

The origin of the phrase "lose steam" is uncertain, but it likely comes from the idea of a steam engine losing power as the pressure in its boiler decreases. This phrase is often used in informal or casual language to describe situations where someone or something was once moving forward with energy and enthusiasm, but has since slowed down or come to a stop.