Short Answer: The spending capacity of an individual (or household).
Detailed Answer: It is money that can be used to purchase luxury items, vacations, and other non-essentials. It's EXTRA money that's left over,
AFTER all non-essential expenses have been paid.
Many people don't realize what their discretionary income actually is, which causes OVERSPENDING.
This is the reason they aren't able to save any money. And this is also why everyone should know what their discretionary income is.
Once you know your discretionary income, you should not overspend it, if saving money is a goal.
To find out your discretionary income, just create a budget. It's very easy to do and only takes a few minutes!