A very large marine mammal (Trichecus rosmarus) of the Seal family, native of the Arctic Ocean. The male has long and powerful tusks descending from the upper jaw. It uses these in procuring food and in fighting. It is hunted for its oil, ivory, and skin. It feeds largely on mollusks. Called also morse.
- A large marine mammal (Odobenus rosmarus) of Arctic regions, related to the seals and having two long tusks, tough wrinkled skin, and four flippers. Also called sea horse.