flatline

1. The effect caused after a severe case of insomnia in which you collapse immediately and sleep.

2. Used to describe an extreme measure of sleep. Incidentally this closely relates to the term "you can sleep when you're dead."

I didn't want to go anywhere, I had terrible sleep and when I came home from school I flatlined on the bed.

Person A: Hey where's Adam?
Person B: He got shitfaced and flatlined somewhere in the kitchen.

by xKRASHx August 28, 2010

Flatlíne

Awesome paladin tank on the horde side of the Bronzebeard EU server.

"Man that Flatlíne is the shizzle"

Known for his wit, handsome good cow looks, and ability to abuse bad dps.

Omg its Flatlíne. Watch your threat before he pwns you

by angryqqer August 21, 2011

Flatline

The act of not responding to a text, email, chat, or message.

So I got this girl's number at a party, but when I texted her, she flatlined me.

The guy accepted me on facebook, but whenever I chat him he flatlines me

by partyrocklifestyle November 13, 2011

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.

by Thetunacan99 February 9, 2023

Emotional Flatliner

Someone who shows no emotional response to anything, no matter how poignant or stirring. They’re either so repressed that nothing gets through their emotional firewall, or so disconnected from their feelings that even a child’s laugh, a heartfelt poem, a soulful song, or a breathtaking view leaves them completely unmoved. Picture a human equivalent of a flatline on an emotional EKG—zero reaction, just a blank stare.

"I played her my favorite song, the one that makes everyone cry, and she just shrugged—total Emotional Flatliner."

by Raquel de la Roche August 5, 2025

Flatlings

Large, saggy, flat breasts

"Jesus Christ! Did you see the flatlings on that lady?

by Scummy Smith December 10, 2009

flatline

To have intercourse with a person in a rough, physically hurtful manner to the point where their consciousness or life is in question. An exageration of having intercourse to the point of someone dying.

I flatlined that ass so hard she was crying.

by c0d1 February 18, 2011