If your text is automatically hyphenated and certain hyphenated words look ugly, or if you want specific words never to be hyphenated you can switch off hyphenation for those words:
Choose LibreOffice - PreferencesTools - Options - Language Settings - Writing Aids
Select a dictionary in the \<emph\>User-defined dictionary \</emph\>list, and then click \<emph\>Edit\</emph\>.
If the list is empty, click \<emph\>New\</emph\> to create a dictionary.
In the\<emph\> Word\</emph\> box, type the word you want to exclude from hyphenation, followed by an equal sign (=), for example, "pretentious=".
Click \<emph\>New\</emph\>, and then click \<emph\>Close\</emph\>.
To quickly exclude a word from hyphenation, select the word, choose \<emph\>Format - Character\</emph\>, click the \<emph\>Font \</emph\>tab, and select "None" in the \<emph\>Language \</emph\>box.
Some words contain special characters that LibreOffice treats as a hyphen. If you do not want such words to be hyphenated, you can insert a special code that prevents hyphenation at the position where the special code is inserted. Proceed as follows:
Position the cursor at the place where no hyphenation should occur.
The inserted formatting mark will be shown in gray. To remove it, simply place the cursor over the formatting mark and press the Del key.