noun · a light used for security or safety purposes, such as an emergency light or a motion-sensor light.

这盏安全灯在天黑时会自动亮起。

noun · A light source used in photographic darkrooms that provides illumination without fogging light-sensitive materials.

在暗室洗照片时，只能开启红色安全灯。

noun · A lamp designed for use in hazardous environments, such as mines, to prevent explosions.

矿工进入矿井前必须检查安全灯是否完好。