I apologize Marco...I thought you were wanting to not have that Add a new entry button show up at all, so I was thinking maybe a different activity would fit your needs better.
Glossary
"Add a new entry" button on Glossary
ការពិភាក្សាត្រូវបានបិទ ដូច្នេះអ្នកមិនអាចឆ្លើយតបទៀតទេ។