German orthography
Compound words, including nouns, are written together, e.g. "Haustür" (Haus+Tür; house door), "Tischlampe" (Tisch+Lampe; table lamp), "Kaltwasserhahn" (Kalt+Wasser+Hahn; cold water tap/faucet). This can lead to long words: the longest word in regular use, "Rechtsschutzversicherungsgesellschaften" ("legal protection insurance companies"), consists of 39 letters; while the longest German word ever published ("Donaudampfschiffahrtselektrizitätenhauptbetriebswerkbauunterbeamtengesellschaft", "Association for subordinate officials of the head office management of the Danube steamboat electrical services") has 79 letters.
Historical dictionary
The largest historical dictionary of German is the "Deutsches Wörterbuch" originally compiled by Jacob and Wilhelm Grimm and completed after their death in 1961. A second edition of the letters A–F is due for completion in 2017.