-miente | OEDoS

-miente (archaic) Adverb-forming suffix akin to "-ly." Early 13th cent. Old Spanish -mientre, under contamination from -iter, and -miente. All but entirely replaced by -mente, which was originally a dialect variant. From Vulgar Latin *-mente. "In modern Spanish, -mente is no longer perceived as a noun (its congener miente is now confined to a few idiomatic expressions), but it can still be detached from its host adjective in order to avoid awkward repetition.... ~ Harris & Vincent, The Romance Languages (2003) Dictionnaire Étymologique Roman. Online. Ed. by É. Buchi & W. Schweickard. 2018. http://www.atilf.fr/DERom.