Subtopic (noun)

A topic that is a division or aspect of a more general one.

Origin:

Late 19th century: from sub- + topic.

Examples:

1. This chapter contains several subtopics on the history of the region.
2. The speaker will discuss the subtopic of sustainable agriculture.
3. The subtopic of health care reform is very complex and controversial.
4. The subtopic of renewable energy is gaining more attention due to environmental concerns.
5. The subtopic of cross-cultural communication will be explored in greater depth in the next section.