WordWeight : Weighing the Words

Pronunciation : Dem`on*stra"tion
Part of Speech : n.
Etymology : [L. demonstratio: cf. F. d?monstration.]
Definition : 1. The act of demonstrating; an exhibition; proof; especially, proof beyond the possibility of doubt; indubitable evidence, to the senses or reason. Those intervening ideas which serve to show the agreement of any two others are called "proofs;" and where agreement or disagreement is by this means plainly and clearly perceived, it is called demonstration. Locke.

2. An expression, as of the feelings, by outward signs; a manifestation; a show. Did your letters pierce the queen to any demonstration of grief Shak. Loyal demonstrations toward the prince. Prescott.

3. (Anat.)

Defn: The exhibition and explanation of a dissection or other anatomical preparation.

4. (Mil.) a decisive exhibition of force, or a movement indicating an attack.

5. (Logic)

Defn: The act of proving by the syllogistic process, or the proof itself.

6. (Math.)

Defn: 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 (Logic & Math.), one in which the correct conclusion is the immediate sequence of reasoning from axiomatic or established premises; -- opposed to Indirect, or Negative, demonstration (called also reductio ad absurdum), in which the correct conclusion is an inference from the demonstration that any other hypothesis must be incorrect.
Source : Webster's Unabridged Dictionary, 1913