The Doctor on trial. (TV: The Mysterious Planet)
In law, a defendant was one who was accused of a crime. A trial was to determine the defendant's guilt or otherwise on the basis of the evidence that was presented. On Gallifrey, a court defender would be appointed to represent a defendant to ensure that their interests were fully protected, though they could deny such representation if they so wished. (TV: The Mysterious Planet, The Ultimate Foe)