Sleeper

Sleeper

Noun · /ˈsliːpə/ · three meanings hiding in one quiet word

Definition

A sleeper is, first, a person or animal that sleeps — especially one described by how they sleep: a light sleeper wakes at the slightest sound; a heavy sleeper can sleep through almost anything. Second, a sleeper is a railway carriage fitted with beds for overnight travel, or the entire overnight train itself. Third, and most intriguingly, a sleeper is something that achieves unexpected success after a long quiet period: a sleeper hit, a sleeper film, a sleeper stock. In intelligence and espionage, a sleeper agent lies dormant inside an organisation for years before being activated. In all three meanings, the word carries the idea of hidden potential — something resting, waiting, not yet awake to its full power.

Origin

From Old English slēpere, meaning one who sleeps. The railway sense developed in the nineteenth century when overnight sleeping cars became common on long-distance routes. The "hidden potential" sense emerged in twentieth-century American entertainment journalism to describe films or albums that sold slowly at first, then became cultural phenomena. The espionage sense followed naturally — a sleeper agent, like a sleeper hit, is something dormant that eventually wakes up with dramatic effect.