Which of the following terms describes a small pole from which a flag is flown?

The term that describes a small pole from which a flag is flown is "staff." In flag terminology, a staff is specifically designed for the purpose of displaying a flag and is typically shorter and more portable than a traditional flagpole. It is often used in ceremonial contexts or for smaller flags that are meant to be carried or displayed in more intimate settings, such as at parades or events.

While "halyard" refers to the rope used to raise and lower a flag, "flag pole" generally denotes a more substantial and taller structure meant for flying larger flags. "Union" refers to the portion of the flag that holds the stars in the United States flag, rather than a pole for displaying the flag. Thus, the usage of the term "staff" aptly conveys the concept of a small pole specifically intended for flag display.