So I decided to buy a commercial dictionary...
The free ones are OK (Wordnet-DICT was my favorite), but if you need to find all and not just basic forms, you do need to buy one.
My choice finally was "
LONGMAN Dictionary of Contemporary English 5th edition" which has a very reasonable price + FREE Thesaurus and Collocations Dictionary.
Works like a charm and finds each and everything... *YIPPIEH*
Note: Pronunciation is shown in a very small size (not really readable), but I don't need this + some colored text is shown in a very light grey.
BTW: One still can't find things like "top hat", "white collar crime" and the like... But that would need changes in the CyBook software (the possibility to mark more then just 1 word).
