A Commodity (n.) is a very strange thing, abounding in metaphysical subtleties and theological niceties.
A Commodity (n.) is an external object, a thing that by its properties satisfies human wants of some sort or another.
A Commodity (n.) is produced for exchange rather than something produced for immediate use or consumption by the producer.
A Commodity (n.) has a value because it is a crystallization of social labor. The greatness of its value, or its relative value, depends upon the greater or less amount of that social substance contained in it... that is to say, on the relative mass of labor necessary for its production.
The Commodity's (n.) circulation is the original precondition of the circulation of money.
The Commodity (n.) is the cornerstone of capitalism and commodity production is a key defining characteristic.