demencyEtymologyFrom Latin dēmentia, from dēmens (“out of one's mind”).demency means madness; dementia. Lexicurio rates it Sui generis — a strength score of 87 out of 100.nounMadness; dementia.“no direct access could be obtained to the banned, or burned, books of the three cosmologists, Xertigny, Yates and Zotov (pen names), who had recklessly started the whole business half a century earlier, causing, and endorsing, panic, demency and execrable romanchiks.”