sleeper meaning and definition

SLEEPER noun

Definition of sleeper (noun)

1. a rester who is sleeping
   • synonyms: slumberer
2. 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
3. an unexpected achiever of success
   • "the winner was a true sleeper--no one expected him to get it"
4. one of the cross braces that support the rails on a railway track
   • "the British call a railroad tie a sleeper"
   • synonyms: crosstie, railroad tie, tie
5. a passenger car that has berths for sleeping
   • synonyms: sleeping car, wagon-lit
6. pajamas with feet; worn by children
7. a piece of furniture that can be opened up into a bed
8. tropical fish that resembles a goby and rests quietly on the bottom in shallow water
   • synonyms: sleeper goby
9. an unexpected hit
   • "that movie was the sleeper of the summer"