sleeber 

The MOST sleeby person you know. An expert sleeper. A master of naps. Someone who can sleep at the drop of a hat anytime anywhere.

Cindy sat down for just a second and is already out cold. She's just a tiny sleeber!

sleeber by BKValuemeal May 18, 2021

sleeper hit 

Generally any type of media that is marketed as under the radar, yet is of quality to have been a top tier marketing tool.

"That game is definately a sleeper hit, easily worth my twenty dollars!"

sleeper hit by Senior Twinkles May 28, 2006

sleeper car 

A car that has high performance but intentionally looks to be ordinary or even beat up. The polar opposite of a rice burner.

Did you see that sleeper car waste the Ferrari yesterday?

sleeper car by Napoleon the Clown July 12, 2006

Sleeper Peeper 

A boner that arises at the moment when you are close to falling asleep, but becomes so uncomfortable that you must push back your sleep and instead focus on getting the boner flaccid. Typically one rids themselves of this type of erection by removing underwear or whatever they were sleeping in, and then not letting the peeper touch anywhere else, as that may keep the boner going. It may take awhile.

Dude 1: Yo man I got no sleep last night.
Dude 2: Damn that sucks. What happened?
Dude 1: Sleeper peeper bro. Shit didn't go away for hours.
Dude 2: I feel you dude.

Sleeper Peeper by Dang Lin Wang LXIX August 19, 2013

Sleeper Build

A physique that is not appealing to the naked eye until it is flexed or uncovered, normally someone that looks small but big when flexing.

Lol look at Oscar he’s so fucking puny, oh shit damn look at that sleeper build who would’ve thought ?!

Sleeper Build by BabyZay September 27, 2022

Ricer-Sleeper 

A vehicle, usually an import tuner, that is heavily modified under the hood (built engine, forced induction etc), capable of being faster than most other modified cars, however has non-performance damaging flamboyant cosmetic modifications (stickers, a large spoiler, hood/roof scoops, large obnoxious muffler).

A ricer-sleeper accomplishes being a sleeper (a car that does not look fast but really is) by appearing to be a ricer (a car that is modified to look cool and fast but in reality is not).

Guy 1: OMG! LOOK AT THAT RICER! Looks like he took the Fast and Furious trend too far...

Guy 2: LAWL YES, i bet it's a stock, base model, automatic!

Guy 3: That thing just beat my 300HP Nissan 5 minutes ago...

Guy1: OMGAWD its a sleeper??

Guy2: OH SHIZ! It's a ricer-sleeper.

Ricer-Sleeper by poopnikker February 18, 2011

no-sleeper 

A no-sleeper is the corporate equivalent to a no-hitter - a presentation in which nobody dozes off.

Kurt had a no-sleeper going until he got to the financing options slides - then he lost it. Badly.

no-sleeper by PsychoPuppyDad August 1, 2014