There's a meme that German has a word for everything, and I'm often asked what the German word for some complicated phrase is.
My answer is usually, "There isn't one, but I can make one up for you." (Occasionally there actually is a word for that, like Kummerspeck, weight gained from emotional overeating (literally "grief bacon"), but not most of the time.)
It's very true that German has a lot of long compound words, but the vast majority of them (especially the 5- and 6-word conglomerations) won't be in the dictionary. Yes, Donaudampfschifffahrtsgesellschaftskapitän is a word, and it has a Wikipedia entry that is largely composed of its usage in machine translation problems and examples of artificial and fictive words composed from it. (I am still of the opinion that it should be Schiffahrt, the Rechtschreibreform be damned. Three f's in a row look ridiculous.)
The German language has a very useful and convenient property that allows for the building of compound (or composite) words, known in German as Komposita. All you need is a stem noun and another noun, an adjective or adverb, or sometimes a verb, which you glom onto the front of the stem noun (sometimes with modifications). Each subsequent addition makes the thing more specific.
Let's use Kapitän as a first example, since we've got the lovely Komposita up there. You have a Kapitän--a captain. You can have a Mannschaftskapitän (a team captain; two nouns) or a Schiffskapitän (a ship captain). Bastian Schweinsteiger is currently the Nationalmannschaftskapitän (national team captain; adjective and two nouns, and the adjective makes the first noun more specific).
Another example: Teller (plate). You can have a Gemüseteller on a menu, and it will be a plate of vegetables. Or you can buy a very nice Porzellanteller, which is a plate made of porcelain. You don't always just smush words together. You wouldn't have a Grünporzellanteller, but you would have a grünen Porzellanteller, if it's green.
It is very convenient to make compound words in German where we would have two words or sometimes a phrase in English. But it's a myth that words for every esoteric concept exist in German. You won't find it in a dictionary, but if you're nice, maybe a German speaker will make one up for you.