The term 'Astrolabe PLATE' is a combination of two words: 'Astrolabe' and 'PLATE'. An Astrolabe is an ancient astronomical instrument used to measure the positions of stars and planets. A PLATE is a flat, round object with a hole in the center. The RETE is the part of the Astrolabe that holds the star maps and is used to locate the stars and planets. It is made up of a series of concentric circles with pointers that indicate the position of the stars and planets.