aquatic digitigrade carnivorous mammal, hunted for its fur, Middle English oter, from Old English otr, otor "otter," from Proto-Germanic *otraz "otter" (source also of Old Norse otr, Swedish utter, Danish odder, Dutch otter, Old High German ottar, German Otter), from PIE *udros, literally "water-creature" (source also of Sanskrit udrah, Avestan udra "otter;" Greek hydra "water-serpent," enydris "otter;" Latin lutra, Old Church Slavonic vydra, Lithuanian ūdra, Old Irish odoirne "otter"), from root *wed- (1) "water; wet." The sea otter of the U.S. Pacific Northwest is attested from 1660s, also known as sea-ape.