1. (

• sleeper ,
• slumberer

) a rester who is sleeping ;

2. (

• sleeper ,

) 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. (

• sleeper ,

) an unexpected achiever of success; "the winner was a true sleeper;

4. (

• tie ,
• railroad_tie ,
• crosstie ,
• sleeper ,

) one of the cross braces that support the rails on a railway track; "the British call a railroad tie a sleeper" ;

5. (

• sleeping_car ,
• sleeper ,
• wagon-lit

) a passenger car that has berths for sleeping ;

6. (

• sleeper ,

) pajamas with feet; worn by children ;

7. (

• sleeper ,

) a piece of furniture that can be opened up into a bed ;

8. (

• sleeper ,
• sleeper_goby

) tropical fish that resembles a goby and rests quietly on the bottom in shallow water ;

9. (

• sleeper

) an unexpected hit; "that movie was the sleeper of the summer" ;