青信号|あおしんごうaoshingou[3]nakadaka (mid-high)

1. noungreen light (traffic)
   青信号あおしんごうで道路どうろを渡わたりましょう。↗

   Only cross the street on the green light.
2. noungreen light; go-ahead signal; permission to go ahead (with something)

• Synonym青色信号WrittenThe written/formal-prose way to say 「青信号」, mostly seen in explanatory text; in everyday speech people just say 「青信号」.
• Antonym赤信号あかしんごうNeutralThe red light that tells you to stop; by extension, a sign of danger. It stands opposite 「青信号」, which signals that one may go ahead.

For both the traffic light and the figurative go-ahead, say 「青信号」; 「青色信号」 is a more written/formal alternative. The antonym 「赤信号」 is the red light meaning stop, or a sign of danger.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 行いくことが安全あんぜんであることを知しらせる青色あおいろまたは緑色みどりいろの灯火とうか信号しんごう。古ふるくは「緑みどり信号しんごう」とも呼よばれた。
2. 計画けいかくなどをそのまま進行しんこうさせてもよいというしるし。