Definitions of demonstrate:

• verb:   march in protest; take part in a demonstration

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

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

  Example: "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

  Example: "This decision demonstrates his sense of fairness"

• verb:   show or demonstrate something to an interested audience