Definition of absentees:
(n) :
A person who is absent from his or her employment, school, post, duty, etc.
(n) :
A voter who is not present at the time of voting; absentee voter.
(n) :
(attributive) Designating a person absent in a particular capacity, sometimes implying that they are difficult to contact, unresponsive, avoiding their responsibilities, etc.
(n) :
(law) A person who is absent from their residence and usual environment, and has not been seen or heard from for some period of time, so that it is unknown whether they are still alive, for the purpose of civil law dealing with the management of property etc. in such cases.
(n) :
(attributive) Designating something whose owner, person responsible, etc. is absent.
(n) :
Something that is not present where it might be expected.