köken: From Middle High German vūl, from Old High German fūl, from Proto-West Germanic *fūl, from Proto-Germanic *fūlaz, from Proto-Indo-European *puH-lo-s (“rotten, putrid”). Compare Dutch vuil, English foul, Danish ful, Swedish ful. Doublet of Foul. The sense “lazy” developed in part from the idea of food rotting when lying around, in part from the notion that idleness is morally rotten.
aile: auf der faulen Haut liegen, faulen, Faulholzmotte, faulig, Fäulnis, Faultier, oberfaul, stinkfaul
köken: From *yalqag(u) (“lazy”), from the verbal stem yalq- (“to be annoyed, to have had enough of sth., to loathe, be disgusted”). Cognate with Kazakh жалқау (jalqau), Bashkir ялҡау (yalqaw), Southern Altai јалку (ǰalku), Uzbek yalqov, Uyghur يالقاۋ (yalqaw), Tuvan чалгаа (çalgaa, “lazy”), etc.
köken: From *yalqag(u) (“lazy”), from the verbal stem yalq- (“to be annoyed, to have had enough of sth., to loathe, be disgusted”), see ялҡыу (yalqıw), probably related to ял (yal, “rest”). Cognate with Kazakh жалқау (jalqau), Kyrgyz жалкоо (jalkoo), Southern Altai јалку (ǰalku), Uzbek yalqov, Uyghur يالقاۋ (yalqaw), Tuvan чалгаа (çalgaa, “lazy”), etc.
köken: From Middle Dutch loy, from Proto-Germanic *lujaz. further etymology unsure. May be cognate with the Old Norse adjective lúinn (“exhausted”). Perhaps from Proto-Indo-European *lewH- (“to cut off, separate, free”), source of Proto-Germanic *lausaz, Albanian lirë.
aile: liever lui dan moe, luiaard, luibak, luie donder, luie stoel, luierik, luiheid, luilak, luilap, luilekker
köken: First attested in the Seokbo sangjeol (釋譜詳節 / 석보상절), 1447, as Middle Korean 게으르다 (Yale: keyGuluta). Compare Yukjin Korean 게그르다 (gegeureuda), preserving the original /k/.