"A situation in which a single company owns all or nearly all of the markett for a given type of product or service. This would occur in the case where there is a barrier to entry into the industry that allows the single company to operate without compettition,( for example vast economies of scale; barriers to entry or governmental regulation.) In such an industry structure the producer will often produce a volume that is less than the amount that would maximise social welfare."
Thats the economists definition of Monopoly; which by the way I never said Wal-Mart was; I said it utilised monopolistic practice to shut down other suppliers.
But actually it is the real definition of a "Monopsony". You can look that up if you want to know something about this subject.
As to your last statement I would suggest you do the research as this looks like you are completely in the dark regarding basic economics.