Anyone who is not present or who is not in a certain place at a given time; unaccounted for; nonexistent person: Shawn was an absenter who missed more classes than he attended.

As a joke, the student club at the university decided to give an award to the most outstanding absenter, the one who missed most of his or her classes!

At the awards ceremony, there was a tie with two absenters because they were not present for the same number of times.