Fare thee well means ‘may things go well for you’! ‘Fare thee well’ appears in a lot of songs - often about sending people on a journey safely and happily, saying ‘goodbye and safe journey’ - although it is really about ‘the journey of life’ not exclusively, travelling. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.