The word 'unscramble' is a modern English formation built upon the verb 'scramble', which emerged in the late 16th century with meanings related to clambering or struggling, later evolving to signify mixing things together in a disorderly fashion. The Germanic prefix 'un-', one of the oldest and most productive in English, is attached to indicate the act of reversing this process. Thus, the literal construction means "to reverse the mixing," which perfectly captures its modern applications, from restoring a muddled transmission to solving a word jumble. Its logic is transparent, representing a direct application of a native prefix to a later verb to create a term for restoring order from chaos.

Structure: un (reversal) + scramble (to mix up) - un: A prefix of Germanic origin (Old English un-, on-), used to indicate reversal, deprivation, or the opposite of an action. - scramble: A verb of uncertain origin, perhaps a blend of 'scrabble' and 'crawl', meaning to mix, climb, or move hastily and disorderly.