Some languages, like icelandic and norwegian, use combined words. Where words can be combined to make longer words. Other languages, such as english, usually keeps the words separate. That way, in icelandic and norwegian, we can build very long words. I don't know what the longest word is in norwegian, but I do know that some guy made the word visebuljongterningpakkemesterassistent. It's a fake job title.

"minoritetsladningsbærerdiffusjonskoeffisientmålingsapparatur" is the longest word in Norwegian :3
You also have this, but its chemistry:
"methionylglutaminylarginyltyrosylglutamylserylleucylphenylalanylalanylglutaminylleucyllysylglutamylarginyl lysylglutamylglycylalanylphenylalanylvalylprolylphenylalanylvalylthreonylleucylglycylaspartylprolylglycylisol eucylglutamylglutaminylserylleucyllysylisoleucylaspartylthreonylleucylisoleucylglutamylalanylglycylalanylaspartyl alanylleucylglutamylleucylglycylisoleucylprolylphenyl alanylserylaspartylprolylleucylalanylaspartylglycylprolyl threonylisoleucylglutaminylasparaginylalanylthreonylleucyl arginylalanylphenylalanylalanylalanylglycylvalylthreonyl prolylalanylglutaminylcysteinylphenylalanylglutamylmethionylleucylalanylleucylisoleucylarginylglutaminyllysyl histidylprolylthreonylisoleucylprolylisoleucylglycylleucylleucylmethionyltyrosylalanylasparaginylleucylvalylphenyl alanylasparaginyllysylglycylisoleucylaspartylglutamylphenylalanyltyrosylalanylglutaminylcysteinylglutamyllysylvalyl glycylvalylaspartylserylvalylleucylvalylalanylaspartylvalylprolylvalylglutaminylglutamylserylalanylprolylphenylalanyl arginylglutaminylalanylalanylleucylarginylhistidylasparaginylvalylalanylprolylisoleucylphenylalanylisoleucylcysteinyl prolylprolylaspartylalanylaspartylaspartylaspartylleucylleucylarginylglutaminylisoleucylalanylseryltyrosylglycyl arginylglycyltyrosylthreonyltyrosylleucylleucylserylarginylalanylglycylvalylthreonylglycylalanylglutamylasparaginyl arginylalanylalanylleucylprolylleucylasparaginylhistidylleucylvalylalanyllysylleucyllysylglutamyltyrosylasparaginyl alanylalanylprolylprolylleucylglutaminylglycylphenylalanylglycylisoleucylserylalanylprolylaspartylglutaminylvalyllysyl alanylalanylisoleucylaspartylalanylglycylalanylalanylglycylalanylisoleucylserylglycylserylalanylisoleucylvalyllysylisol eucylisoleucylglutamylglutaminylhistidylasparaginylisoleucylglutamylprolylglutamyllysylmethionylleucylalanylalanylleucyl lysylvalylphenylalanylvalylglutaminylprolylmethionyllysylalanylalanylthreonylarginylserin"

@NorseNorwegian Lol, I dare anyone who has 3 hours to kill to try and pronounce that (yes, it takes 3 hours to say it all correctly)

You can make it even longer. VaðlaheiðarvegavinnuVERKAMANNAverkfærageymsluskúraútidyralyklakippuhringur

Not a real word, just something created specifically to be a long word ;) But grammatically correct, and often treated as the longest word in Icelandic.

http://www.visindavefur.is/svar.php?id=460