Any fire hard to quench.

野火；不易扑灭的火。

A highly flammable composition difficult to extinguish when ignited, formerly used in warfare.

易燃难熄之物；昔日用于战争之燃烧剂。

Lightning, unaccompanied by thunder.

(无雷的)闪电。

The ignis fatuus or a similar light.

磷火；鬼火。

Erysipelas or some similar disease.

丹毒类疾病。