1.
yellow traffic light; amber signal
The yellow light on a traffic signal that appears between green and red, indicating that drivers should prepare to stop.
黄信号で止まった。
I stopped at the yellow light.
黄信号で加速するのは危険だ。
Accelerating on a yellow light is dangerous.
交差点に差しかかったとき、ちょうど黄信号に変わった。
Just as I reached the intersection, the light turned yellow.
2.
warning sign; cause for concern
A figurative signal that something is heading in a dangerous or problematic direction. Used for health, relationships, business situations, and other domains where trouble is brewing.
健康に黄信号がともった。
A warning sign appeared regarding my health.
売上の減少は経営に黄信号だ。
The decline in sales is a warning sign for the business.
最近残業が続いていて、体調に黄信号が出ている。
I've been working overtime a lot lately, and there are warning signs for my health.
Composed of 黄 (yellow) and 信号 (signal, traffic light). The literal meaning refers to the amber phase of a traffic light, but the figurative sense — a warning that something is going wrong — is equally common in everyday Japanese.
The figurative use typically appears with verbs like ともる (to light up), 点く (to turn on), or 出る (to appear), creating vivid imagery of a warning light switching on.
COMMON COLLOCATIONS:
- 黄信号がともる: a warning light comes on
- 黄信号が点く: a caution signal lights up
- 黄信号が出る: a warning sign appears
- 健康に黄信号: a health warning sign
- 経営に黄信号: a business warning sign
SIMILAR WORDS:
- 赤信号: red light — a more severe warning; also used figuratively for imminent danger
- 青信号: green light — literally a green traffic light; figuratively, permission or approval to proceed
- 警告: warning — a direct verbal or written warning, less metaphorical than 黄信号