Is there a way to have a dictionary or file of some sort “attached” to an individual file that can have special words that would only be useful for spellchecking that file. For example you might want to write a fantasy novel with made up words that you do not want to add your standard.dic but still do a spell check to see that they were correct.
You could create a user-defined dictionary ‘fantasy’
(only enabled if required: ☐ fantasy / 
fantasy).
Details
- Help (F1) offline → Index: user-defined dictionaries;editing
- Help (F1) online → http://help.libreoffice.org/Common/Writing_Aids#User-defined_dictionaries