How to create dictionary using c#

Generally to create dictionaries for languages (e.g. English, French ), people use dictionary APIs (which are already available as webservices) on back end and provide a GUI on front end to interact that dictionary.

Here are some links: 
http://stackoverflow.com/questions/6695725/creating-english-dictionary-desktop-application

http://stackoverflow.com/questions/5160615/english-language-dictionary-api

and a project:

http://www.codeproject.com/Articles/61265/GCIDE-A-Complete-English-Language-Dictionary

Hope it would help you...