noun
[noncount] loose earth or soil
a substance (such as mud or dust) that makes things unclean
informal :a person or thing that has no value
informal :information about someone that could harm the person's reputation
To dig up (the) dirt on someone is to find out information that is harmful to that person's reputation.
To dish (the) dirt is to spread harmful gossip or information.
hit the dirt
in the dirt
In baseball, a pitch is in the dirt when it hits the ground near home plate before reaching the catcher.