"divination by means of melted wax dripped in water" (the shapes supposedly previsioning a future spouse, etc.), 1650s, from French ceromancie, Medieval Latin ceromantia; see cero- "wax" + -mancy "divination by means of."
word-forming element meaning "wax, waxy," from Latinized form of Greek kēros "beeswax," a word of unknown origin with no obvious ulterior connections. "As there is no evidence for Indo-European apiculture, we have to reckon with foreign origin for κηρός" [Beekes].
word-forming element of Greek origin meaning "divination by means of," from Old French -mancie, from Late Latin -mantia, from Greek manteia "oracle, divination," from mantis "one who divines, a seer, prophet; one touched by divine madness," from mainesthai "be inspired," which is related to menos "passion, spirit" (from PIE *mnyo-, suffixed form of root *men- (1) "to think," with derivatives referring to qualities and states of mind or thought). Compare mania.
<a href="https://www.etymonline.com/word/ceromancy">Etymology of ceromancy by etymonline</a>
Harper, D. (n.d.). Etymology of ceromancy. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/ceromancy