loess; yellow sand; dust from the Yellow River region
Refers to wind-borne yellow dust, especially from arid regions of China. In modern Japanese, 黄砂 (こうさ) is the usual term; 霾 is a rare, literary, or technical synonym.
See also: 黄砂 (こうさ)
In classical texts, the character 霾 sometimes refers to yellow sand.
春になると、ばいが飛来して空がかすむ。
In spring, loess blows in and the sky becomes hazy.