yellow flag

• 表示警告或提醒注意的信号或标志，常用于体育（尤其是赛车）中指示赛道上的危险或障碍，也比喻性地指潜在的麻烦或风险。

A warning signal or cautionary indicator, often used in sports (especially motorsports) to signal danger or a hazard on the track, or metaphorically to indicate potential problems or risks in a situation.

1. Racing signalB2formal

   A yellow flag displayed in motorsports to indicate a hazard on the track, requiring drivers to slow down and not overtake.

   黄旗

   • The race was interrupted by a yellow flag after the crash.
   • Drivers must reduce speed when a yellow flag is shown.
   • The yellow flag remained out for several laps due to debris on the track.

2. Warning signB2informal

   A metaphorical warning or indicator of potential danger or a problem.

   警告信号

   • His sudden change in behavior was a yellow flag for his friends.
   • The company's declining profits are a yellow flag for investors.
   • She saw his lack of communication as a yellow flag in their relationship.