Powder Monkey
When sailing was a common profession, young boys used to tag along with sailors going off to war. Powder monkeys were such youngsters. It’s been said that “monkey” originated from the phrase “monkeying around,” but there’s no proof for it.
These youngsters were required to carry bags of gunpowder from one point to another and then fill the ship’s cannons with powder in order for the sailors to get ready for battle.