The first computer mouse (1964)   The English word mouse has been around longer than the English language has.   Its origin is in the Proto-Germanic word m ū s , which is also a word for the rodent.   It gave rise to the Old English mous and mowse , the German Maus , and the Dutch muis .   The reason the word has the peculiar plural form of mice is due to a process known as cheshirization, where a change in the way certain sounds in a language change, but an obsolete phonological distinction gets reclassified as a new form.   To make this simpler, mice is descended from the Proto-Germanic m ūsiz, which is the form of the nominative and vocative declensions of m ūs .   You need not know what a declension is, except that the vocative declension no longer exists in English (not as a distinct, marked form, at least).   The only way a declension changes the modern English word mouse is when we use the possessive declension mouse’s ....