An Etymological Dictionary of the German Language/Annotated/Leiste
Leiste (1.), feminine, ‘list, border, selvage,’ from Middle High German lîste, Old High German lîsta, feminine, ‘long strip, edge, lace, list’; compare Anglo-Saxon lîst, feminine, English list; Icelandic lísta (lĭsta?), feminine, ‘border, strip’; in the non-Teutonic languages there are no cognates. Note, however, the words borrowed in Romance Italian lista, French liste, ‘strip, lace.’
Leiste (2.), feminine, ‘groin,’ Modern High German only, probably not connected with the preceding word, but with Gothic *laistô, feminine. The latter is indicated also by English last (dialectic), ‘groin.’ The equivalent Anglo-Saxon leósca, Middle English lêske, Modern Dutch liesche, Old Swedish liuske, Danish lŷske, diverge too widely in sound from the High German form; the attempt to connect it with Middle Latin laisius, ‘lap’ (Lex Salica), is also dubious.