To show or make something clear by giving proof or evidence. The scientist demonstrated the effectiveness of the new drug through a series of experiments.
To show or express a feeling or quality through actions or behavior. She demonstrated her commitment to the project by working overtime.
To show how something works or how to do something. The chef demonstrated how to prepare the dish step by step.
To take part in a public protest or march to express opposition or support for something. Thousands of people demonstrated against the new policy in the city center.