We do not currently know of any synonyms for dipleidoscope.
The noun dipleidoscope is defined as:
An instrument for determining the time of apparentnoon. It consists of two mirrors and a planeglass in the form of a prism, so that, by the reflections of the sun's rays from their surfaces, two images are presented to the eye, moving in opposite directions, and coinciding at the instant the sun's centre is on the meridian.