The dictionaries directory contains files that YaCy can use to generate - better 'did you mean' hints - annotated content for search navigation (future feature) These files are once read and translated into a YaCy-internal format. To integrate dictionaries, you must download them separately in store them in DATA/DICTIONARIES/source You can do that with the following files: Korpusbasierte Wortgrundformliste DeReWo des Institut für Deutsche Sprache: derewo-v-30000g-2007-12-31-0.1.txt from http://www.ids-mannheim.de/kl/derewo/derewo-v-30000g-2007-12-31-0.1.zip