That which describes or explains information, opinions, etc.: The expository speech that the university president, Mr. Anderson, made helped soothe the anxieties of major donors.

Speeches that inform, more than attempt to persuade: Each of the candidates gave a five minute expository speech to explain their party's policies.

The purpose of an expository speech is to describe, to clarify, to illustrate, or to define an object, an idea, a concept, or some kind of process.