Demonstrate (verb)

1. To show clearly and deliberately by reasoning or evidence.
2. To manifest openly or publicly.
3. To display the operation or use of (a product or service).
4. To show (a quality or feeling) by one's actions.
5. To march or assemble in a public demonstration.

Origin:

From latin "demonstratus", past participle of "demonstrare" (to show), from "de-" (completely) + "monstrare" (to show).

Examples:

1. The experiment was conducted to demonstrate the effectiveness of the new drug.
2. The protesters demonstrated against the government's decision to raise taxes.
3. The salesperson will demonstrate the features of the new phone to the customers.
4. The athlete demonstrated great determination and perseverance during the competition.
5. The students plan to demonstrate in front of the school to demand better facilities.