Probation refers to a trial period of a new employee; this period can vary depending on the position and the organization, however it is usually from 3-6 months; this period allows employers to assess  performance and skills of the new employee. During a probation period, the employee is not entitled to all employee benefits as they are still in their trial period.

If the employee does not meet the requirements during the probation period, the employer usually ends the employment relationship. 

Part of speech:
Use in a sentence:
The employee is on probation.