What is the longest word in Wales and its interpretation?

The longest word in Wales is a place name - 'Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch.' It literally means 'St. Mary's Church in the hollow of the white hazel near a rapid whirlpool and the Church of St. Tysilio of the red cave' - it is a description of the place. This long name was invented in order to encourage tourists to Llanfair; tourists stopped to take a look because the name sign of the village was longer than its train station!