Compound (linguistics)
Agglutinative languages tend to create very long words with derivational morphemes. Compounds may or may not require the use of derivational morphemes also.
The longest compounds in the world may be found in the Finnic and Germanic languages. In German, extremely 
extendable compound words can be found in the language of chemical compounds, where, in the cases of biochemistry and polymers, they can be practically unlimited in length, mostly because the German rule suggests combining all noun adjuncts with the noun as the very last stem. German examples include (color television set), (radio remote control), and the often quoted jocular word (originally only two Fs, Danube steamboat shipping company captain['s] hat), which can of course be made even longer and even more absurd, e.g. "Donaudampfschifffahrtsgesellschaftskapitänsmützenreinigungsausschreibungsverordnungsdiskussionsanfang" ("beginning of the discussion of a regulation on tendering of Danube steamboat shipping company captain hats") etc. According to several editions of the Guinness Book of World Records, the longest published German has 79 letters and is " Donaudampfschiffahrtselektrizitätenhauptbetriebswerkbauunterbeamtengesellschaft "("Association for Subordinate Officials of the Main Electric[ity] Maintenance Building of the Danube Steam Shipping"), but there is no evidence that this association ever actually existed. The word is so absurd that it was obviously invented as a joke, which is emphasized by the illogical use of the plural of "electricity".
Northern Germany
Although from the 19th century onwards the use of Standard German was strongly promoted especially by the Prussian administration, Low German dialects are still present in rural areas, with an estimated number of five to eight million active speakers. However, since World War II and the immigration of expellees from the former eastern territories of Germany, its prevalence has steadily reduced. Besides which, Frisian is spoken in East and North Frisia, as well as Danish (Standard and South Jutlandic) in parts of Schleswig. From a linguistic and cultural perspective, Northern Germany is linked to the Netherlands, Scandinavia and England. For example, the German word for butcher is "Fleischer" or "Metzger" in the middle, east or south of Germany but is called a "Schlachter" in Northern Germany, resembling the Scandinavian terms for butcher, "slagter/slakter". Other examples are the word for potato, which is "Erdapfel" in much of Southern Germany, Austria and Switzerland, but "Kartoffel" in Northern Germany and in Danish; the North German verb "kieken" (meaning to look), resembling the Danish "kikke/kigge", or Norwegian "kikke" (to look); or the word for the fruit orange, which is "Orange" in standard German, but "Apfelsine" in Northern Germany, similarly to the Dutch ("appelsien/Sinaasappel"), Frisian ("aapelsiin") and Scandinavian languages ("appelsin/apelsin"). Additionally, Jansen/Janssen, Hansen, and Petersen are the most common surnames in the far north of Germany (Lower Saxony and Schleswig-Holstein), which are also some of the most common surnames in Denmark (albeit with "Jensen" for Jansen). Hansen is the single most common surname in Norway, the third most common surname in Denmark, and the third and fifth most common surname in the North German federal states of Schleswig-Holstein and Hamburg, respectively.