Definition of discretion noun from the Oxford Advanced Learner's Dictionary

Academic

discretion

noun
dɪˈskreʃn
 
; dɪˈskreʃn
 
[uncountable]
 
1 the freedom or power to decide what should be done in a particular situationI'll leave it up to you to use your discretion.How much to tell terminally ill patients is left to the discretion of the doctor.2 care in what you say or do, in order to keep something secret or to avoid causing embarrassment to or difficulty for somebody; the quality of being discreetThis is confidential, but I know that I can rely on your discretion.Jane is the soul of discretion(= you can trust her).Use the utmost discretion when you talk to her. compare indiscretion
Idioms

at somebody's discretion

according to what somebody decides or wishes to do
Bail is granted at the discretion of the court.There is no service charge and tipping is at your discretion.

discretion is the better part of valour

(saying) you should avoid danger and not take unnecessary risks