someone who is boring, unenergentic, tired, sleepy.
Dont be a flatliner! Here's a beer, c'mon lets get drunk!
by DanteM August 03, 2005

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Top Definition
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.
by D*Tice June 08, 2003

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A heart stopper. Someone that completely makes your heart stops in awe.
Man, that Emma girl, is a total flatliner.
by CxmeronL49 April 08, 2017

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A person who has died, referring to the heart monitor "flat lining", as can be seen in any film featuring an emergency room death.
When Ray makes love to a women, she may say, "it was like sex with a flat liner!"
by Mark J. February 23, 2006

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A person whos eyebrows lack an arch.
Gentleman: Hon, you should really pluck your eyebrows, you look like a total flatliner.
Woman: Thanks, Hon.
by LadyGagum November 26, 2009

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Name given to a attractive person who "makes your heart stop"
That girl, she's a flatliner
by Heyfu April 23, 2017

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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?"
by Dick Asplundher May 08, 2009

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