The term 'Russian Horse-Drawn Vehicle' can be summarized as a TROIKA, which is a six-letter word. A TROIKA is a traditional Russian vehicle that is pulled by three horses harnessed side-by-side. It was used for transportation and racing in the 19th century and is still used today in some parts of Russia for ceremonial purposes. The TROIKA is an iconic symbol of Russian culture and is often featured in Russian art and literature.