Defendant
A defendant was a person or entity that was being sued in a civil case, or accused of a crime in a criminal case.
James T. Kirk was the defendant in a court martial following the death of Benjamin Finney. (TOS: "Court Martial")
The next most senior officer on the starship of a defendant was tasked with prosecution in cases where the captain defended his crewman. (TNG: "The Measure Of A Man")
In Cardassian trials, the nestor was not allowed to address the court, only assist the defendant. (DS9: "Tribunal")
Information accessed from a private database could only be used in court with a search order or the defendant's permission. (DS9: "Rules of Engagement")
Benkaran justice allowed wealthy defendants to negotiate a financial settlement with the family of the victim. (VOY: "Repentance")