Rum, originated in the West Indies, with records mentioning the affirmed tipple in 1650, rum started out being called “kill-devil” or “rumbullion” but by 1667 it was simply referred to as rum.
Now where's the pirate link? Well....
Rum, being distilled from sugar, was relatively cheap to transport and so became a staple export. This meant that many of the ships attacked by pirates were laden with barrels of rum, just ripe for the picking. Although rum could fetch a good few pieces of eight, the stolen loot was mainly supped by pirates and that's the link right there, almost every pirate ship had rum aboard and almost every pirate drank rum.
Rum nowadays has flavours aplenty, with Dead Man's Fingers coming up with some weird and wonderful concoctions - Lime rum anyone?