The definition of discretionary is something that you use as desired or needed.
When you have petty cash available to you to use, the money you spend is an example of discretionary spending.
- left to or regulated by one's own discretion or judgment: an appointee with discretionary powersalso dis·cre′tional
- administered by a proxy: a discretionary investment account
- Left to or regulated by one's own discretion or judgment.
- Available for use as needed or desired: a discretionary fund.
(comparative more discretionary, superlative most discretionary)