walrusyoudaoicibaDictYouDict
walrus: [17] Etymologically, a walrus is probably a ‘whale-horse’. The word seems to have been borrowed from Dutch walrus, which was an inversion of a presumed prehistoric Germanic compound represented by Old English horschwæl and Old Norse hrosshvalr. (The inversion may have been due to the influence of Dutch walvisch ‘whale’ – literally ‘whale-fish’ – but it could also owe something to French influence, since French noun compounds of this sort are often in the reverse order to corresponding Germanic ones.) The element wal- is clearly the same word as whale, and -rus is generally assumed to be horse.

It has, however, been suggested that the horsc- of the Old English term was an alteration of morsa, a name for the walrus of Lappish origin which is also the source of French morse ‘walrus’.

=> horse, whale
preposterous (adj.)youdaoicibaDictYouDict
1540s, from Latin praeposterus "absurd, contrary to nature, inverted, perverted, in reverse order," literally "before-behind" (compare topsy-turvy, cart before the horse), from prae "before" + posterus "subsequent." Related: Preposterously; preposterousness.