"Catoptromancy" refers to a form of divination that relies on mirrors. While this word may not be familiar to everyone, there are a few synonyms that might be easier to remember. For example, "scrying" is a term for using a crystal ball, mirror, or other reflective surface to gain insight into the future. Similarly, "crystallomancy" refers specifically to divination using crystal or glass objects. Finally, "mirror-gazing" is a more straightforward term that describes the act of using a mirror to see visions or receive messages from beyond. While these words may not be used frequently in everyday conversation, they all describe the same practice of using mirrors to access the unknown.