The social science that deals with the production, distribution, and consumption of goods and services and with the theory and management of economies or economic systems.
The above is a poor definition of 'economics' because it includes the misleading phrase "... and management ...". No one can manage an economy. Economists study the principles of economics in order that they may predict the result of this policy or that one, but their predictions are always guesses, and are often wrong to a greater or lesser degree.
Because economists (try to) predict economic outcomes, non-economists surmise that the process can be run in reverse: that we can start at the effect we wish and back into the policy that will deliver that effect. It is an attractive fallacy, and we need no more proof than the hot messes and dumpster fires of failed economies that got where they are because some politician had sufficient hubris to believe that economies can be managed. No one can manage an economy. There is no person or group of persons, no matter their educational credentials, who can force an economy to behave as they wish.
The only way to 'manage' an economy is to get out of its way. Any politician who tells you s/he can fix the economy's shortcomings is either lying or stupid. If they don't themselves believe what they're saying, they think you're stupid. If you believe them, you are.
Beyond that, economics is a 'social science'. Social sciences are not sciences no matter the name assigned to them. The 'scientific method' involves four major activities: observation, hypothesis, experimentation, and analysis. Implicit in this is that the results are shared among other scientists who replicate the experiment(s) to ascertain that the published results are, indeed, replicable and not one-off flukes. For most (if not all) social sciences, experimentation is difficult-to-impossible, and replication of results likewise difficult-to-impossible. Social sciences thus fail the test of being actual science and so reside in the realm of theoretical pursuits. Few, if any, economic nostrums can be guaranteed to work as predicted, and often fail spectacularly.
No one can manage an economy.