dating slang
red flag
Meaning
- A warning sign that someone is a bad romantic prospect.
- Used loosely for any bad habit or trait worth avoiding in a partner.
“He said his ex was crazy in the first five minutes. Red flag.”
Where it came from
“Red flag” has meant a warning signal in English for well over a century, from railway signals to political symbolism. Dating and relationship discourse adopted it as shorthand for a bad sign in a partner, and the phrase surged across TikTok and Twitter dating discourse starting around 2021.