language and dictionary

[nikow]

Forgive novice question: I am using libreoffice to learn / read / write an 
unsupported language -a dialect of Franco-Norman. Is it possible to use a null 
dictionary and add all the words from scratch? If I can get a few hundred words 
into it, my learning process would be greatly enhanced. I guess conlang writers 
must do something like this when they create new langages. Thanks for reading. 
Nick