What is Aggregate Supply?

Legal Definition
In economics, aggregate supply (AS) or domestic final supply (DFS) is the total supply of goods and services that firms in a national economy plan on selling during a specific time period. It is the total amount of goods and services that firms are willing and able to sell at a given price level in an economy.
-- Wikipedia
Legal Definition
All goods and services at any level in an economy. AKA total output.