Definition of 'sleeper'
- a rester who is sleeping
- a spy or saboteur or terrorist planted in an enemy country who lives there as a law-abiding citizen until activated by a prearranged signal
- an unexpected achiever of success; "the winner was a true sleeper--no one expected him to get it"
- one of the cross braces that support the rails on a railway track; "the British call a railroad tie a sleeper"
Synonyms: tie railroad tie crosstie
- a passenger car that has berths for sleeping
Synonyms: sleeping car wagon-lit
- pajamas with feet; worn by children
- a piece of furniture that can be opened up into a bed
- tropical fish that resembles a goby and rests quietly on the bottom in shallow water
Synonyms: sleeper goby
- an unexpected hit; "that movie was the sleeper of the summer"