red flag 

a sign or warning of any impending danger, disaster or doom

when my gf called me up that day and gave me the "we need to talk" line, a red flag obviously came up and I figured I'd soon be on the outs with her.

red flag by Bungalow Bill November 18, 2006

Red flag 

A 'red flag' is a term used to describe when somebody has a feeling that they are potentially dealing with a manipulative and/or possibly psychotic or sociopathic individual. It's usually used to explain a feeling after the fact.

It was a red flag when she told me that she had four kids from four different men.

Red flag by NotoriousBigG July 6, 2019

red flag 

1. a warning sign

2. subject to a warning

A funnel cloud is a red flag for the formation of a tornado.

red flag by The Return of Light Joker October 15, 2009

red flag 

a bad sign of what’s to come

I think the first red flag was when my supposed date started lying to me a lot.

red flag by nlolhere June 29, 2020

red flag 

Stopping what you're doing because because something has made the environment unsafe. Derived from the racing flag that is used to stop a race because of unsafe conditions.

"We're red-flagged at this gas station because it's snowing too hard for us to be able to go on."

red flag by D2RCR January 31, 2004

Red Flag 

Krow and Casey

Fuck you guys

Krow and Casey are the biggest red flags I’ve ever seen

Did you hear what krow said about Casey in art class? Major red flag

Red Flag by Fuckkrowandcasey March 25, 2022

Red flag 

A 'red flag' is a term used to describe when somebody has a feeling that they are potentially dealing with a manipulative and/or possibly psychotic or sociopathic individual. It's usually used to explain a feeling after the fact.

He didn't like Louis Tomlinson, I should've seen that red flag.
He dislikes Louis Tomlinson, you can't ignore that red flag, you have to drop him.
Stream defenceless, that is not red flag

Red flag by Idk every pseudonym is used February 6, 2021