Grist is the ground malt and grains ready for mashing.
Many distilleries will have grist rooms (or cupboards) as even though it’s just keenly shredded and ground cereal - their fine particle nature are immensely flammable and create problems if not controlled. Gristing machines are also very loud, so there’s an added advantage of not having to listen to one roar directly too!
Gusano is a term for the larvae “worms” that can be found in bottles of Mezcal.
The worm is actually the larva from a type of moth known as a maguey worm, which lives on the agave plant. The practice of adding a worm began in the 1950’s as a marketing ploy and today, while many consider it to be a gimmick, some brands bottle theirs with them in and on the label you will find the words, Con Gusano.
Golden refers to a style of rum, although it’s quite loose as a genre given there are no official regulations around it.
Some gold rums see the inside of a barrel for a few months or years, but many are simply white rums dyed with additives. Because of that most producers who bottle aged rum without colouring refer to their products simply as aged rum and typically, you can expect a Golden Rum to derive its hue is from colouring and /or contain extracts of some kind.