Walrus
early 18th century: probably from Dutch walrus, perhaps by an inversion of elements (influenced by walvis ‘whale fish’) of Old Norse hrosshvalr ‘horse whale’.
wiktionary
Probably borrowed from Dutch walrus, a compound of wal(“whale”) and ros(“horse”). Displaced native Old English horshwæl(literally “horse whale”). Compare similar constructions in Danish hvalros, Old Norse hrosshvalr, and German Walross.
etymonline
walrus (n.)
"large pinniped carnivorous mammal" (the males are noted for their enormous tusk-like canine teeth), 1650s, from Dutch walrus, which was probably a folk-etymology alteration (by influence of Dutch walvis "whale" and ros "horse") of a Scandinavian word, such as Old Norse rosmhvalr "walrus," hrosshvalr "a kind of whale," or rostungr "walrus." Old English had horschwæl, and later morse, from Lapp morsa or Finnish mursu, which ultimately might be the source, much garbled, of the first element in Old Norse rosmhvalr.
