If you gave a speech in a dream, then such dream indicates the confidence and belief in yourself you have. The dream could also mean that you need to tell something important for a certain person or community. Alternatively, the dream may indicate your actual fear of speaking in public in front of many people. If you heard someone else saying a speech in a dream, then it means that you are ready to take the advices that others gave to you. Make sure you heard what the speech was about as it would give much more information about the dream.
Read more about dreaming of Speech in other dream meanings interpretations.