Sea otter \Sea" ot"ter\ (Zool.) An aquatic carnivore ({Enhydris lutris} syn. {Enhydris marina}) found in the North Pacific Ocean. Its fur is highly valued, especially by the Chinese. It is allied to the common otter, but is larger, with feet more decidedly webbed. [1913 Webster] {Sea-otter's cabbage} (Bot.), a gigantic kelp of the Pacific Ocean ({Nereocystis Lutkeana}). See {Nereocystis}. [1913 Webster]