1. Having feet resembling fins, fin-footed; specifically, belonging to a suborder (Pinnipedia) of Carnivora, comprising the seals and walruses, which have fin-like limbs or flippers; also, belonging to other divisions of animals having limbs or organs resembling fins and adapted for swimming, e.g. the fin-footed or lobe-footed birds, certain decapod crustaceans or crabs, the pteropod molluscs, etc.
2. A pinniped mammal; a seal or walrus.