Dĕm'on-strā'tion, n.

n. [Lat. demonstratio, Fr. démonstration, Sp. demostracion, Pr. demonstratio, It. dimostrazione. See DEMONSTRATE.]

1Sense 1. The act of demonstrating, showing, or making clear; an exhibition; indication; revelation; proof; evidence; especially, proof beyond the possibility of doubt; the proof itself thus presented.

Those intervening ideas which serve to show the agreement of any two others are called “proofs;” and where the agreement or disagreement is by this means plainly and clearly perceived, it is called demonstration. Locke.

2Sense 2. An expression of the feelings by outward signs; a manifestation; a show. “Loyal demonstrations toward the prince.” Prescott.

He was compelled by the national spirit to make a demonstration of war. Hallam.

3Sense 3. (Anat.) The exhibition of the parts of a subject that has been prepared by the dissector.

4Sense 4. (Logic.) The act of proving by the syllogistic process, or the proof itself.

5Sense 5. (Math.) A course of reasoning showing that a certain result is a necessary consequence of assumed premises; these premises being definitions, axioms, and previously established propositions.

Direct or positive demonstration, that which concludes with the direct and certain proof of the proposition in question. — Indirect or negative demonstration, that which proves a proposition to be true by showing that the supposition of its falsity involves an absurdity; — called also reductio ad absurdum. Playfair.

6Sense 6. (Mil.) A decisive exhibition of force, or a movement indicating an intention.