To manage words in your dictionary, first click on the menu item Main menu\Options\Dictionary\Other options. From the dialog box shown below, perform these steps:

1. select a customized dictionary, 

2. type the new word in the edit box labeled as Word, 

3. specify the appropriate action that must take place for  each occurrence. (Automatic replacement, ignore...). 

4. click on the button "Add Word".

To remove a word from the custom, perform these steps:

1. Select the customized dixtionaries, 

2. Select the word from the combo box labeled as Word. 

3. Once selected, please click on Remove word