Definition of tail off

The phrase "tail off" originated in the 1950s and 60s in the context of sports, particularly athletics and racing. It was used to describe the gradual decrease in speed or performance towards the end of a competition or event. The term "tail" in this context refers to the back end or final stages of a race. It comes from the shape of the hindquarters of an animal, which tapers to a narrow end. In the case of a horse, for example, the end of its back can resemble a tail. When a horse's speed starts to decline in the final stretch of a race, it is said to have "lost its tail" or "had its tail fall off". This indicates a significant drop in pace and performance, as if the horse's energy and determination have suddenly vanished. The expression "tail off" expanded beyond the world of sports to describe any decline or decrease in progress, productivity, or success over time. It is often used to describe a situation where an initial burst of enthusiasm or effort is not sustained, such as in business, marketing, or project management. In summary, "tail off" derives from the way a horse's hindquarters resemble the end or "tail" of a race, and was originally used to describe a sudden decline in speed in that context. It has since become a common phrase that is used to denote any decrease or slowdown in performance or productivity.