Flatliner 

A heart stopper. Someone that completely makes your heart stops in awe.

Man, that Emma girl, is a total flatliner.

Flatliner by CxmeronL49 April 8, 2017

Flatliner 

Name given to a attractive person who "makes your heart stop"

That girl, she's a flatliner

Flatliner by Heyfu April 23, 2017

flatliner 

Someone severely lacking in personality; a person who kills any festive mood with their utter dullness

Dottie was having a good time, until she got stuck with that flatliner.

flatliner by D*Tice June 8, 2003

flatliner 

someone who is boring, unenergentic, tired, sleepy.

Dont be a flatliner! Here's a beer, c'mon lets get drunk!

flatliner by DanteM August 29, 2005

Flatliner 

A person whos eyebrows lack an arch.

Gentleman: Hon, you should really pluck your eyebrows, you look like a total flatliner.
Woman: Thanks, Hon.

Flatliner by LadyGagum November 26, 2009

Flatliner 

A mindless person or someone with no personality; gives blank stares, especially when presented with ideas or facts that should arouse some sort of reaction in a sentient being. Basically brain dead or mentally challenged. It would be improper to use this against someone who has a real diagnosed disability of course. More like, if you meet someone in a professional capacity whose title suggests they are intelligent, but really they just stand around looking dumb.

"I told Guido that the server was down and he said 'So...?'. Is that guy a fucking flatliner?"

Flatliner by Dick Asplundher May 8, 2009

Flatliner 

When you’re fucking a diabetic so hard her insulin pump fails sending her into insulin shock only to be revived by cumming in her mouth.

Hey Tina. I hope your glucose levels are in check or else we might have a flatliner.

Flatliner by Thetunacan99 February 9, 2023