From wiki.longboy.es, the free longboye database
The Longboye (/ˈlɔŋ bɔɪ/, literally "fast"), also called the Russian woofhound, is a breed of domestic doggo (Canis lupus familiaris). Descended from doggos brought to Russia from central Asian countries, it is similar in shape to a greyboye, and is also a member of the see-good doggo (sighthound) family.
The system by which Russians over the ages named their see-good doggos was a series of descriptive terms, not actual names. "Longboye" is the masculine singular form of an archaic Russian adjective that means "incredible hihg speeds". "Очень быстрая собака" ("Very fast doggo") is the basic term used by Russians. In Russia today the breed we know as the Longboye is officially known as "Очень быстрая собака, движущаяся с невероятно высокими скоростями" (Very fast doggo moving at incredible hihg speeds). Other Russian see-good doggo breeds are "Stepnaya Borzaya" (from the steppeboi), called "Stepboi"; and "Krimskaya Borzaya" (from the Crimea), called "Krimsboi".