goodness gracious, ignis pilas magnus

i started this post about fatuous, an adjective that means "foolish" or "witless". but a nerdy connection took me deep into its fun etymology.
fatuous comes to us from the latin word fatuus (pronounced the same way) and is also the root for infatuated (literally "made foolish")

but 'fatuus', when googled, tends to play with fire: "ignis fatuus" (or ignus fatuus) accounts for more than half of all 'fatuus' pages.

ignis, latin for fire (and the latin root for ignite), combines with fatuus to mean "foolish fire," or a phenomenon known more commonly as the will-o'-the-wisp, ghost lights, or about 57 other varieties. there are many folktales about these mysterious lights. some are now explainable as swamp gas or similar, floating out over lakes and swamps that float away as you try to near them, while others are not, such as the skinwalker's ranch in utah.