sleeper

IPA: sɫˈipɝ

Someone who sleeps.
That which lies dormant, as a law.
A spy, saboteur, or terrorist who lives unobtrusively in a community until activated by a prearranged signal; may be part of a sleeper cell.
A small starter earring, worn to prevent a piercing from closing.
A railway sleeping car.
(martial arts, wrestling) A sleeper hold.
Something that achieves unexpected success after an interval of time.
A goby-like bottom-feeding freshwater fish of the family Odontobutidae.
A nurse shark (family Ginglymostomatidae).
A type of pajama for a person, especially a child, that covers the whole body, including the feet.
(slang) An automobile which has been internally modified to excess, while retaining a mostly stock appearance in order to fool opponents in a drag race, or to avoid the attention of the police.
(slang) A sedative.
(slang, gambling) A bet placed on the gambling table and then forgotten about by the gambler.
(science fiction) A pod or similar device containing a person in cryosleep.
(rail transport, Britain) A railroad tie.
(carpentry) A structural beam in a floor running perpendicular to both the joists beneath and floorboards above.
(nautical) A heavy floor timber in a ship's bottom.
(nautical) The lowest, or bottom, tier of casks.
A surname.

Examples of "sleeper" in Sentences

The sleeper train chugged slowly through the night, carrying passengers to their destination
The old armchair in the corner of the room was a comfortable sleeper for anyone in need of a nap
The sleeper agent had been living a double life for years, waiting for the perfect moment to strike
The quarterback threw a perfect pass to the wide receiver, who had been a sleeper pick in the draft
The sleeper hit movie took everyone by surprise, becoming a cultural phenomenon overnight