A radical, who hides his or her beliefs in order to prevent suspicion from any authority figure; an extreme liberal who pretends to be a conservative, usually for gaining money to fund a revolution.
James Cole believed a schizophrenic person was going to release the virus; it turned out a sleeper did the job.
by Vash Westland August 24, 2003
Often reffering to what appears to be a ordinary looking stock commuter car that is anything but stock under the hood. Pretty much the exact opposite of your every day riced up civic.
My bone stock looking 1967 Volkswagen Beetle with a dual carbed, big bore and race head equiped engine gives quite the ego bashing when a ricer can't hold up to his own challenge at a light.
by VWtuner June 06, 2003
Outwardly common looking item, that possesses something special or unique inside.
That boring looking car is a real sleeper with that big turbo hiding under the hood and nary a sticker or scoop to be seen anywhere on it.
by sageoneon March 07, 2003
Large, beautiful breasts that are keep well consealed and initially appear to be much smaller and less impressive than they actually are until unleashed.
I think Alicia may have some real sleepers.
by KABT October 26, 2007
A car that looks stock on the outside but is putting out some serious power under the hood.
"Damn, your car is freaking fast! You planning on putting a bodykit or drag spoiler on it?"
"Nah, I prefer the sleeper look."
"Nah, I prefer the sleeper look."
by dragonfly12345 February 07, 2006
The exact opposite of a ricer. A Sleeper looks stock but is heavily modified to preform better. Sleepers are often, like ricers, economy cars. Unlike ricers, sleepers can also be regualr sedans or any other vehicle that was not meant to be a preformance vehicle. Sleeper cars are ussually modified with boost (super or turbochargers), transmisions, and sometimes full engine swaps. Many people who drive sleepers use them to hustle at the strip or avoid attention from the cops. Many auto makers offer factory sleepers that are a sport version of the origional economy sedan with very few external changes. Some of the best sleepers of all time came from the muscle car era. The 1972 Chevy Nova is considered one of the best sleepers. The Nova is one of the most popular models to get turned into a sleeper. Most sleepers aren't true sleepers because they will have aftermarker gauges visible (real sleepers hide them in the glove box), racing slicks and loud pipes. A true sleeper will not be exposed until they reach the end of the track.
Chuck's 1968 Mustang GT500 got spanked by a 1960 Chevy Nomad Wagon. Chuck was the victim of a big time Sleeper when the Nomad lifted the front wheels in the air and he proceeded to see nothing but tail lights down the track.
by northendwhitetrash August 04, 2008
A chick that you don't think is hot at first, but after a period of time, you come to the conclusion that this girl is very hott.
Yea, this girl is a sleeper. I didn't think she was hot at first, but after a brief period of time, I came to the conclusion that she is very hott.
by Ryaun December 09, 2006
a person who is an outwardly common looking item, but possesses something special or unique inside
Cyndi turned out to be a sleeper, I thought she was just a bar fly but she has an M.A.Sc. in Electrical Engineering and owns half a restaurant with her youngest uncle.
by Jake March 24, 2004