The term 'Orient Expresser' is a reference to the famous Orient Express train, which was a long-distance passenger train service that operated from 1883 to 2009. The term is often used to refer to someone who travels on the Orient Express, or someone who is experienced in traveling on the Orient Express. The crossword solution for the term 'Orient Expresser' is POLO, which is a reference to the game of POLO, which was popular among passengers of the Orient Express.