To "delate" someone is to "hand down" that person to a court of law. In Latin, "delatus" is the unlikely-looking past participle of deferre, meaning "to bring down, report, or accuse," which in turn comes from ferre, meaning "to carry." Not surprisingly, our word defer, meaning "to yield to the opinion or wishes of another," can also be traced back to "deferre." At one time, in fact, "defer" and "delate" had parallel meanings (both could mean "to carry down or away" or "to offer for acceptance"), but those senses are now obsolete. Today, you are most likely to encounter "delate" or its relatives "delation" and "delator" in the context of medieval tribunals, although the words can also relate to modern ecclesiastical tribunals.