Meaning 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

Synonyms: sleeper goby

noun

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

noun

pajamas with feet

noun

a passenger car that has berths for sleeping

Synonyms: sleeping car wagon-lit

noun

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

Example: "the British call a railroad tie a sleeper"

Synonyms: tie railroad tie crosstie

noun

a rester who is sleeping

Synonyms: slumberer

noun

an unexpected achiever of success

Example: "The winner was a true sleeper--no one expected them 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