Changing some of the words used

From MoodleDocs

If you have installed Moodle and want to change one or two of the words Moodle uses (for example, if the word "course"/"courses" is not appropriate for your context), simply follow the "Making small customisations" instructions in the Translation instructions. You can define your "localised" strings in a separate file, which means they won't be overwritten when you upgrade Moodle.