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

For one former Saint Alphonsus physician assistant who spoke to the Statesman, Shapiro’s decision-making in surgery became a red flag. — Nicole Blanchard, Idaho Statesman, 16 July 2026

Understanding the gravity of a red flag warning and adhering to these precautions is pivotal in mitigating the risk of wildfires during these perilous conditions. — Ca Weather Bot, Sacbee.com, 15 July 2026

Mold inhibitors—often listed as calcium propionate—are a key red flag. — Olivia McIntosh, Martha Stewart, 15 July 2026

These ingredients give them a longer shelf life and signature flavor—and also raise red flags for health risks. — Lauren Manaker Ms, Health, 14 July 2026