natural cavern (in limestone)
the depth of winter
Azure Dragon, one of the four symbols of the Chinese constellations, also known as the Azure Dragon of the East 東方青龍|东方青龙[Dōng fāng Qīng lóng] or 東方蒼龍|东方苍龙[Dōng fāng Cāng lóng]
lit. cut sleeve (idiom); fig. euphemism for homosexuality, originating from History of Western Han 漢書|汉书: emperor Han Aidi (real name Liu Xin) was in bed with his lover Dong Xian, and had to attend a court audience that morning. Not wishing to awaken Dong Xian, who was sleeping with his head resting on the emperor's long robe sleeve, Aidi used a knife to cut off the lower half of his sleeve.