Just to be clear for two-masted ships: on a ketch or yawl, the shorter mast is aft, while on a schooner, the shorter is to the fore -- whichever one is shorter is the mizzen-mast, regardless of position. The word was first used in the early 15th century. Like most nautical jargon, the source is obscure -- about the only thing clear about it is that it ultimately comes from Latin medianus, of the middle, but by what route and how the meaning shifted to the rear mast is a mystery. Possible routes include one or more of Spanish mesana (meaning a sail set amidships), French misaine (foremast/mainmast), Catalan mitjana (middle), or Italian mezzana (middle). In short, this middle is all a muddle.
With a thundering crack, the mizzen-topsail tore and the shreds carried away by the gale.