red flag

NOUN

warning signal

Synonyms

WEAK

casus belli delicate subject red light red rag sore point

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

That is always a red flag for me when I’m reading an OLC opinion.

From Slate • Apr. 9, 2026

"He never had a single red flag at all."

From BBC • Apr. 7, 2026

On Feb. 4, it broke above a five-month cup-base pivot of $149.89, but the breakout quickly fizzled—a red flag.

From Barron's • Apr. 6, 2026

And if interviewers bristle at questions or dodge them, that could be a red flag.

From MarketWatch • Apr. 3, 2026

That may not seem like a red flag, but right now it’s a huge one.

From "On the Come Up" by Angie Thomas