Your browser does not seem to support JavaScript. As a result, your viewing experience will be diminished, and you have been placed in read-only mode.
Please download a browser that supports JavaScript, or enable it if it's disabled (i.e. NoScript).
The amount by which the value of an article is increased at each stage of its production, exclusive of initial costs.
Share your knowledge with the community
Browse our collection of 300,000+ community-written definitions