The amount of goods available best defines:

The amount of goods available is known as supply.

Explanation:

The specific goods or services that are available to consumers is known as supply. It can be described as the amount available at a specific price or the amount available across a range of prices. The goods which are available for making specific products are known as the supply. When supply of a product goes up, the price of a product goes down and demand for the product can rise because it costs loss.