What does "burning" mean?

Burning: Consuming; intense; inflaming; exciting; vehement; powerful; as, burning zeal. Like a young hound upon a burning scent. Dryden. Burning bush (Bot.), an ornamental shrub (Euonymus atropurpureus), bearing a crimson berry.

Additional senses

  1. 2.The act of consuming by fire or heat, or of subjecting to the effect of fire or heat; the state of being on fire or excessively heated. Burning fluid, any volatile illuminating oil, as the lighter petroleums (naphtha, benzine), or oil of turpentine (camphine), but esp. a mixture of the latter with alcohol. -- Burning glass, a conxex lens of considerable size, used for producing an intense heat by converging the sun's rays to a focus. -- Burning house (Metal.), the furnace in which tin ores are calcined, to sublime the sulphur and arsenic from the pyrites. Weale. -- Burning mirror, a concave mirror, or a combination of plane mirrors, used for the same purpose as a burning glass.

Sources