1 [with object] clearly show the existence or truth of (something) by giving proof or evidence:their shameful silence demonstrates their ineptitude
show (a feeling or quality) by one’s actions:she began to demonstrate a new-found confidence
2 [with object] give a practical exhibition and explanation of (how a machine, skill, or craft works or is performed):computerized design methods will be demonstrated [with clause]:she demonstrated how to cook chops
3 [no object] take part in a public demonstration:thousands demonstrated in favour of the government