RhymeZone: sleeper definitions

Definitions of sleeper:

noun: an unexpected hit
Example: "That movie was the sleeper of the summer"
noun: tropical fish that resembles a goby and rests quietly on the bottom in shallow water
noun: a piece of furniture that can be opened up into a bed
noun: a rester who is sleeping
noun: an unexpected achiever of success
Example: "The winner was a true sleeper--no one expected him to get it"
noun: 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
noun: a passenger car that has berths for sleeping
noun: one of the cross braces that support the rails on a railway track
Example: "The British call a railroad tie a sleeper"
name: A surname (rare: 1 in 100000 families; popularity rank in the U.S.: #9631)