Definition - What does Absenteeism mean?
Absenteeism is missing work repeatedly without a valid excuse. If it happens often enough, it can be grounds for an employer to fire an employee. Absenteeism does not include work that is missed for legitimate reasons, such as ill health, a death in the family, going into labor, accidents resulting in injuries, etc.
Justipedia explains Absenteeism
An example of absenteeism would be a man who works at a kitchen utensil manufacturing company deciding to simply not show up for work for three weeks due to a desire to play video games when he is supposed to be at work. If the man is absent enough times, then the employer could have legitimate grounds to fire the employee.
Sometimes, there can be debate as to whether or not an employee was fired for legitimate or illegitimate reasons. If an employee believes he or she was fired for unlawful or unjustifiable reasons, then he or she can sue the employer for wrongful termination.