Dig up dirt
Meaning: To seek out negative information about a person
Originated in: 🇺🇸 United States of America
Digging up dirt on someone is an idiomatic way of saying that you are trying to find out bad things about them. This phrase is often used in the context of politics, where candidates and their supporters will try to find negative information about their opponents to use against them. It is also largely used in the context of tabloid “journalism,” where reporters will try to find scandalous information about celebrities to sell more newspapers or magazines. Sometimes people will dig up dirt on someone just as part of personal grudge however.
It is almost solely a negative term. Few “good people” dig up dirt on others. The right thing to do is to forgive and to not spread gossip regardless, but people do it often anyway.
The idiom is a clear extension of the slang term “dirt”, just meaning gossip or incriminating information. To get physical dirt, you have to dig it up, so likewise people “dig up” metaphorical dirt. How much “dirt” implies truthful information versus just baseless gossip varies by usage. Often, as is the phantasmic nature of truth, it will be claimed true and few will be able to tell the difference.