noun
red flag
red FLAG
Red flag (noun) means a sign that something is wrong or dangerous, especially an early warning about a person's behaviour or about a situation you are considering entering. Example: “He wouldn't let her meet his friends, which should have been a red flag.”
noun
1
A sign that something is wrong or dangerous, especially an early warning about a person's behaviour or about a situation you are considering entering.
"He wouldn't let her meet his friends, which should have been a red flag."
"The auditors listed four red flags in the accounts."
2
A flag of red cloth used as a signal of danger, of a stopped or abandoned race, or as an emblem of socialism and revolution.
"The marshals waved a red flag and the race was stopped."
"Red flags flew above the strike headquarters."
verb
1
To mark something as needing attention or as a potential problem.
"The system red-flagged the transaction as unusual."
"Two of the applications were red-flagged for review."
How to use red flag
Learner’s notesIn plain EnglishA warning sign that something is not right.
When to use it
Neutral; extremely common in dating, HR and finance contexts.
Memory tip
Red flags warn you; red herrings mislead you. They are not related.
Trace the full origin ↓
Easily confused with
Common pairings
raise a red flag
major red flag
red flag warning
red-flagged for review
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He wouldn't let her meet his friends, which should have been a _____.
Etymology
From the literal use of a red flag as a warning or stop signal, red being long established as the colour of danger.
Synonyms
View more →Antonyms
green flag
reassurance
Related words
Frequently asked questions
What is the difference between a red flag and a green flag?
A red flag is a warning sign that a person or situation may be harmful; a green flag is the newer, deliberately opposite coinage for a sign that someone is healthy, considerate and worth trusting. Both come from motorsport flagging, where red stops the race and green starts it.
What are examples of red flags in a relationship?
Commonly cited ones include controlling who you see, refusing to take responsibility, love-bombing early on, disrespecting boundaries, and speaking with contempt about every previous partner. A single instance is rarely conclusive; a pattern is what makes it a red flag.
Is "red flag" hyphenated?
As a noun it is two words: a red flag. As a verb it is usually hyphenated or written as one word — red-flagged, red-flagging.
What is the meaning of red flag?
"red flag" (noun) means a sign that something is wrong or dangerous, especially an early warning about a person's behaviour or about a situation you are considering entering.
