A subpoena duces tecum is a court order requiring the person named in it to produce certain books, papers, or other tangible things for the court.
(plural circlets) 1  A crown without arches or a covering. 2  A small circle. 3  A round body; an orb. ( UK, dialect) A circular piece of wood put under a dish at table.
1 Remember that a circle is a locus of points. A circle is all of the points that are a fixed distance, known as the radius, from a given point, known as the center of the circle.  Explore the standard equation of a circle using the applet below (Go here for a larger version)