1. To formally admit and declare that one is guilty of a lesser criminal charge. The defendant pleaded down to a manslaughter charge to avoid the death penalty. He pleaded down to a single charge of perjury in exchange for cooperating with the FBI's investigation of the drug cartel.

2. To receive a lower punishment or prison sentence by formally admitting to a lesser criminal charge. She pled down to 18 months in prison. You might be able to plead down to 10 years, but if you go to trial, you're looking at life in prison.

3. To negotiate a deal with prosecutors or a judge in which a guilty plea is formally made for a lesser criminal charge on someone else's behalf. In this usage, a noun or pronoun is used between "plead" and "down." The defense attorney managed to plead him down to a misdemeanor. He pleaded his client down to a reckless endangerment charge.

4. To negotiate a deal with prosecutors or a judge on someone else's behalf so that they a lower punishment or prison sentence is formally admitting to a lesser criminal charge. In this usage, a noun or pronoun is used between "plead" and "down." I've built a good rapport with the judge overseeing your case, and I think we might be able to plead you down to community service. My attorney pled me down to 15 years in a minimum security prison, which sure as hell beats the prospect of life behind bars.