1. 自由决定的;酌情行事的;便宜行事的
Discretionary things are not fixed by rules but are decided on by people in authority, who consider each individual case.

1. having or using the ability to act or decide according to your own discretion or judgment

e.g. The commission has discretionary power to award extra funds

Synonym: discretional

2. (especially of funds) not earmarked
available for use as needed

e.g. discretionary funds
discretionary income