Surplus

Surplus is when there is more of something  than is needed. Therefore:
If there is more budget than needed, there is a budget surplus. If there is too little, there is a budget deficit
If a business has more of a product available than its customers want to buy at a particular price, an economist would describe the situation by saying the supply is greater than the demand and there would be a "surplus" of the product at that particular price
In Marxian economics, there are surplus product and surplus value.
 Surplus (movie), a 2003 Swedish documentary movie about consumerism