Synonyms of red flag

red flag

noun

as in red light

something that tells of approaching danger or risk

the résumé she accidentally left on the office printer was a red flag that she was planning to quit

Synonyms & Similar Words

• red light
• warning
• handwriting on the wall
• sign
• wake-up call
• tocsin
• tip-off
• signal
• indicator
• caution
• notification
• premonition
• omen
• buoy
• declaration
• portent
• presage
• announcement
• notice
• foretaste
• knell
• foretoken

Antonyms & Near Antonyms

• green light
• permission
• OK
• go-ahead
• all clear

Example Sentences

Recent Examples of red flag

In short, if your skin feels atypical or raises an internal red flag, give your derm a call or schedule an appointment. — Kara Nesvig, Allure, 2 Oct. 2026

Extreme stress, impatience, or intoxication are major red flags that can lead to negative experiences or removal from flights. — Joey Skladany, Travel + Leisure, 29 Sep. 2026

Red flag law The Parkland shooting inspired Florida’s 2018 red flag law. — Romy Ellenbogen Herald, Miami Herald, 29 Sep. 2026

That may sound like a red flag on the surface—some smart feeders technically work without a subscription, but with so many restrictions that you may as well be forced to pay. — Jim Fisher, PC Magazine, 27 Sep. 2026