The term 'OLD NAVIGATION INSTRUMENT' can be summarized as an astrolabe, which is a 9-letter instrument used for navigation in ancient times. An astrolabe is a device that was used to measure the altitude of stars and planets, and was used by sailors to determine their latitude and longitude. It was also used to measure time and calculate the position of the sun and moon. Astrolabes were used from antiquity until the 18th century, when they were replaced by more modern instruments.