One of the great features of LibreOffice Writer is word completion in AutoCorrect. As you use Writer every word longer than a specified size will be collated in the Word Completion list.
Long words are then suggested as you type and automatically completed with the press of Enter. A great time-saver.
Unfortunately the word completion list is wiped after a LibreOffice version upgrade (on Windows anyway, haven’t tested on Linux). Let’s hope the devs can squash this one.