An Etymological Dictionary of the German Language/Annotated/Rohrdommel
Rohrdommel, feminine, ‘bittern,’ from the equivalent Middle High German rôrtumel, masculine; the word has been variously corrupted in Old High German and Middle High German, finally resulting in the Modern High German form. In Old High German occur horo-tukel, horotumil, literally ‘mud, slime tumbler’ (*rôrtumil is not found in Old High German). Middle Dutch roesdomel; Anglo-Saxon has a remarkable form, râradumbla, with the same meaning. The wide diffusion of these cognates, transformed in various ways by popular etymology, but closely resembling one another in sound, leaves to doubt as to their genuine Teutonic origin. The usual assumption that they are all corruptions of Latin crecopulus, cretobolus, onocrotalus won't bear investigation.