A definition speech informs the audience by describing and explaining an object or concept. You might be called upon to deliver such a speech at your place of employment, for example, in order to describe a new business strategy, model or product to company shareholders or other employees. Moreover, if you are a student--and all students are usually required to take public speaking in college--you might be asked to deliver is a definition speech.

Step 1

Write a purpose statement that indicates the direction the speech will take and focuses on its main goal. For example, if you intend to describe the school of philosophical thought known as "transcendentalism," the purpose of your speech might be stated as "to define the meaning of the term transcendentalism and describe its major tenets."

Step 2

State the central idea, which is akin to the thesis statement in an essay and consists of a complete sentence that expresses the main idea or ideas you intend to make. For example, you might say "transcendentalism is a philosophy that proposes that man can discover the nature of reality through thought and spiritual intuition, and its tenets were embraced by such 19th century writers as Henry David Thoreau and Ralph Waldo Emerson"

Step 3

Write the introduction, never forgetting the importance of first impressions. What you initially say can grab the audience's attention or make everyone groan, if not aloud, at least inwardly, and wish they were anywhere but seated there listening to you. According to Stephen E. Lucus, author of "The Art of Public Speaking," you should get the audience's attention by revealing the topic of your speech, establishing your credibility and goodwill, and previewing the main points you intend to make.

Step 4

Write the body of the speech. Since you will have only a certain amount of time in which to deliver the speech, you cannot relate all the facts about a chosen topic. Decide which information is most important and how it will be presented. Begin with a general definition of the object or concept, then explain the major ideas or elements. Provide several illustrations or examples. End the speech by summarizing the main points and/or providing the listeners with sources for additional information.

Step 5

Write the conclusion. Do not end with an abrupt statement such as "this concludes my speech" or "well, that's all I have to say on the topic." Instead, summarize the main ideas that you presented, reinforce the audience's understanding of those ideas and refer back to the central idea that was presented in the introduction. Depending upon the topic of the speech, you might also end with a personal anecdote, appropriate joke or a dramatic statement to leave everyone with something to think about.