An unexpected absentee is someone who was expected to be present but did not show up, often referred to as a 'no-show'. This term is commonly used in the workplace when an employee fails to appear for their shift without prior notification. It can also be used to describe a student who is absent from school without prior notice. Unexpected absenteeism can have a negative impact on productivity and morale, so it is important for employers and teachers to take steps to prevent it.