The term 'Jackrabbit' is a colloquial name for the species Lepus californicus, which is a type of HARE found in western North America. The scientific name for this species is often shortened to 'HARE, ' which is a four-letter word that can be used to solve the crossword puzzle. Jackrabbits are known for their long ears and powerful hind legs, which allow them to reach speeds of up to 45 miles per hour. They are also well-adapted to living in arid climates, and they feed on a variety of plants and small animals.