The term 'Traveler to Cathay' refers to the Italian explorer Marco POLO, who famously traveled to China in the 13th century. His surname is represented by the 4-letter crossword solution 'POLO, ' while his full name is represented by the 9-letter solution 'Marcopolo.' Marco POLO's journey to China was one of the first recorded visits by a European to the Far East, and his accounts of his travels were widely read and influential in Europe.