Определение spent force в Английский Язык Английский Язык словарь
A person, organization, or process which is no longer influential, effective, or robust
Bush already appeared to be a spent force, an unpopular President eking out his final days of power.
If you refer to someone who used to be powerful as a spent force, you mean that they no longer have any power or influence. As a political leader he was something of a spent force