Definition of "Demonstrate" :

verb: establish the validity of something, as by an example, explanation or experiment

"The experiment demonstrated the instability of the compound."

verb: provide evidence for; stand as proof of; show by one's behavior, attitude, or external attributes

"This decision demonstrates his sense of fairness."

verb: give an exhibition of to an interested audience

verb: march in protest; take part in a demonstration

"Thousands demonstrated against globalization during the meeting of the most powerful economic nations in Seattle."