aile: à corps perdu, à fonds perdu, bien perdu, bien connu, cause perdue, cire perdue, pain perdu, peine perdue, rattraper le temps perdu, trou perdu, un de perdu, dix de retrouvés
köken: Probably from Proto-Iranian *wi- (“apart”) + *maiH- (“to harm, damage, fade, decrease”). The prefix is from Proto-Indo-Iranian *wí, from Proto-Indo-European *wí (“apart, away”), and the latter component is from Proto-Indo-European *meyH- (“to lessen, diminish”), from *mey- (“small, little”).
to a lost state, no longer knowing where one is, having lost orientation
köken: vill + -se. Used as an adverb in 1588, based on the adjective vill (“lost”). A few centuries later the adverb was formed into a new adjective vilsen.
köken: From Proto-Albanian *skumba, nasal present from Proto-Indo-European *skewbʰ- (compare English shove, Lithuanian skùbti (“to hurry”), Polish skubać (“to pluck”)). Alternatively, according to Hamp, from Proto-Albanian *humpo.