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

Aldermen have questioned the plan, a potential red flag for credit rating agencies, but the City Council shares broad consensus that the city must find the money to pay one way or another. — Jake Sheridan, Chicago Tribune, 28 Oct. 2026

The poor decision-making, surprisingly shaky accuracy, inability to elevate a weak supporting cast and difficulty moving through progressions quickly are all serious red flags. — Barry Jackson, Miami Herald, 21 Oct. 2026

Players-only meetings are often a red flag and a sign of a team splintering apart. — Steven Johnson, Fort Worth Star-Telegram, 20 Oct. 2026

For a bank or workplace login portal that recognizes your usual login patterns, an unfamiliar IP address or location can raise a red flag. — Kurt Knutsson, FOXNews.com, 20 Oct. 2026