Subtopic

Part of speech: noun

Definitions

1. A specific area of discussion or focus within a larger subject matter
2. a distinct thematic element that contributes to a broader topic
3. a subdivision that helps organize or categorize information for easier understanding

Etymology: "Subtopic" is a plain compound, built from the prefix "sub-" and "topic." The prefix traces back through Latin "sub" ("under, below") to an older Proto-Italic form, ultimately from a Proto-Indo-European root meaning "up" or "under," so the sense is simply "a topic beneath a larger topic." "Topic" itself comes from the Greek "topikos," meaning "of places," from "topos" ("place"), and it reached English through Latin "topica," the title of Aristotle-derived writings on arguments. The word is therefore a straightforward English formation: a smaller heading placed under a main one, with both parts keeping their original senses.