sleeper

noun

1. 1

   an unexpected hit

   that movie was the sleeper of the summer

2. 2

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

3. 3

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

4. 4

   pajamas with feet; worn by children

5. 5

   a passenger car that has berths for sleeping

6. 6

   one of the cross braces that support the rails on a railway track

   the British call a railroad tie a sleeper

7. 7

   a rester who is sleeping

8. 8

   an unexpected achiever of success

   the winner was a true sleeper--no one expected him to get it

9. 9

   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