Internet
red flag
What does red flag mean?
A behaviour or trait, especially in dating, that signals someone could be trouble or unhealthy to be around.
"He talked down to the waiter all night — instant red flag."
Origin
Borrowed from the literal warning flag used in racing and on beaches, it became dating and relationship shorthand online, exploding on TikTok and X in the late 2010s as the negative counterpart to a green flag.
Frequently asked questions
What does red flag mean in slang?
A red flag is a warning sign that a person or situation has a serious problem worth being cautious about.
What does red flag mean in dating?
In dating it's a behaviour that suggests someone may be a bad or unhealthy partner, like dishonesty or disrespect.
What does red flag mean on TikTok?
On TikTok people list red flags to call out concerning behaviour in relationships, friendships, or public figures.
Is red flag the opposite of green flag?
Yes — a red flag warns of problems while a green flag highlights positive, healthy signs.
Study it as flashcards or scroll it in Vocabulary Flow — saved to your collection.
