An animal's tail.

A men's hairstyle whose primary attribute is a braid or ponytail at the back of the head, such as that worn by men in Imperial China.

A line of people, vehicles or other objects, in which one at the front end is dealt with first, the one behind is dealt with next, and so on, and which newcomers join at the opposite end (the back).

To put oneself or itself at the end of a waiting line.

To arrange themselves into a physical waiting queue.

To add to a queue data structure.