The term WEASEL'S AQUATIC RELATIVE is referring to the otter, which is a five letter word. Otters are semi-aquatic mammals that are part of the Mustelidae family, which also includes weasels, badgers, and wolverines. They are found in many parts of the world, including North America, Europe, Asia, and Africa. Otters have long, slim bodies and webbed feet, which help them swim quickly and efficiently. They are carnivorous animals and feed on fish, crustaceans, and other aquatic creatures.