Pronunciation: (dem"un-strā'shun),[key] —n. 1. the act or circumstance of proving or being proved conclusively, as by reasoning or a show of evidence: a belief incapable of demonstration. 2. something serving as proof or supporting evidence: They sent a check as a demonstration of their concern. 3. a description or explanation, as of a process, illustrated by examples, specimens, or the like: a demonstration of methods of refining ore. 4. the act of exhibiting the operation or use of a device, machine, process, product, or the like, as to a prospective buyer.
5. an exhibition, as of feeling; display; manifestation: His demonstration of affection was embarrassing. 6. a public exhibition of the attitude of a group of persons toward a controversial issue, or other matter, made by picketing, parading, etc.
7. a show of military force or of offensive operations made to deceive an enemy.
8. Math.a logical presentation of the way in which given assumptions imply a certain result; proof.