If a person has Lost Their Bottle then they have lost their nerve and bravery. The phrase came from the sport of bare-knuckle prize-fighting around the end of the 19th, and beginning of the 20th century. Each fighter would have a second known as “the bottle man”, whose job was to supply water to them between rounds. Without water a fighter was unable to continue and so, when a fighter was taking a real beating, it was sometimes known for a bottleman to be asked to walk away, to provide an excuse for him not continuing. Over time, the phrase “lost his bottleman” was shortened and more widely to describe cowardly behaviour.