sleeper car 

sleeper car /slēpər kär/ (noun): A chick that looks like a prude and seems shy, but as soon as she has a few drinks or you get her alone, she's up on in!

Dude 1: "Man, that chick I met at the library last night was a free-eak!"

Dude 2: "The chick in the frumpy brown sweater?"

Dude 1: "Total sleeper car, bro."

Dude 2: "Nice!"

sleeper car by Melba_Toast July 28, 2011

Sleeper OP 

Usually in reference a playable video game character . The words "Sleeper OP" means that the character is easy to play and over-powered at the same. So over-powered and easy that you could be asleep and still play them well.

Jim;"Jinx is sleeper OP.. Riot need to gut the fuck out of her"
Kathy;"I agree, fuck that bitch."

Sleeper OP by TheDefinist. January 23, 2015

sleeper-inner 

One who sleeps in often, also avoiding important situations.

George W. Bush is sleeper-inner.

sleeper-inner by E.Ann October 1, 2005

sleeper agent 

a guy who for all appearances is straight, but has a kinsey scale number other than 0.

man, that frat party was full of sleeper agents

sleeper agent by wejak September 24, 2009

Sleeper's Madness 

When some fuckface wakes you up and you try to go back to sleep for a long time, all the while becoming progressively angrier and angrier until you throw back the covers and get up in a fit of rage, thereby abandoning any attempts to salvage sleeping in on your day off from school/work.

Guy 1: "Doctor, this morning I stabbed my roomate in the side of his throat with a harpoon after he woke me up for the fifth morning in a row, ruining yet another morning's rest."
Doctor1: "Dayummm nigga, looks like you dun got yoself one o' da worst cases o' sleeper's madness I ever dun seen in my mo. fuckin. LIFE!!!!"
MedStudent1: "I concur, maybe one day I can clean up my wife's gambling problem and get my finances together to pay off my debts and cure this horrible disease."
Doctor1: "Nigga you best be frenchin' wit me, cuz you ain't neva gonna do dat shit, dis disease be fuckin' INCURABLE, and I would know, I graduated from Harvard Med, top o' ma mofuckin class."

Sleeper's Madness by Scandal123 July 31, 2010

Sleeper Dox

A local "rapper" or "trapstar" who has a false sense of talent and importance.

"damn, that guy is such a Sleeper Dox"

Sleeper Dox by truth-setter March 27, 2015

sleeper and keeper 

When a girl is not a "Fuck and chucker" and worth keeping around because she is awesome.

I'm not sleeping with you till date 5/6 , I want to know you're not a "Fuck and chucker"

...i'm insulted you would even say that, you're clearly a "sleeper and keeper"

sleeper and keeper by Aljolympics June 24, 2016