to burn; to ignite; to light; fig. to spark off (hopes); to start (debate); to raise (hopes)

(attributive) internal combustion

inflammable

to ignite; to start (a fire); (fig.) to spark (debate, conflict etc)

to deflagrate

spontaneous combustion

flashover

to burn without flame; to smolder

fire resistant

burning with no flame; fire beneath the surface; hidden combustion

lit. ashes burn once more (idiom); fig. sb lost returns to have influence; sth malevolent returns to haunt one