The Icelandic language has contributed relatively little to English, which has drawn so heavily on the various languages of the world for its present make-up, but there seems good reason to believe that ramshackle, in its present sense of “tumbledown,” or “on the verge of falling to pieces,” is derived from the Icelandic ramskakkr.
Remember that in the Scandinavian languages, of which Icelandic is one, sk has a value very close to sh in English.
Ramskakkr is made up of the words ramr, “very,” and skakkr, “wry, twisted”; hence is very twisted, and this is very close to what we mean when we call Sonny’s old jalopy a “ramshackle automobile.”
