A missing person is someone who has gone missing and cannot be located. An ABSENTEE is someone who is absent from a place or event without permission or valid reason. A piner is someone who is longing for something or someone, usually in a sad or regretful way. A TRUANT is someone who is absent from school or work without permission or valid reason. All of these terms can be used to describe a missing person, as they all involve someone who is not present in the expected place or situation.