on probation

idiom

Definition of on probation

1 : being tested and watched at a new job to see if one is able to do the job properly As a new employee, I will be on probation for three months.

2 : being allowed to stay out of prison after committing a crime if one behaves well, does not commit another crime, etc. She was arrested while on probation.

3 : being watched for a period of time during which one must behave well in order not to be seriously punished after having made a serious mistake or done something bad He was on probation for cheating. The student was put/placed on probation for copying test answers.