hellfire

What it means

1. uncountableThe fire of Hell.

   The sound of the gang was diminishing into the distance, and the prophet of doom, restored to eloquence, was sending threatful bolts of damnation, hell-fire, and a brimstone gehenna hurtling after them.

   1951, John Wyndham, The Day of the Triffids, Harmondsworth: Penguin Books, published 1954, page 59

2. uncountableFire produced by the Devil, or a similar supernatural creature connected to Hell.
3. broadlycountableA fire that burns with unusual heat or ferocity.

In a sentence

The sound of the gang was diminishing into the distance, and the prophet of doom, restored to eloquence, was sending threatful bolts of damnation, hell-fire, and a brimstone gehenna hurtling after them.

1951, John Wyndham, The Day of the Triffids, Harmondsworth: Penguin Books, published 1954, page 59

Where it comes from

1. Old Englishhellefȳr
2. Middle Englishhelle fire
3. Englishhellfire

From Middle English helle fire, helever, from Old English hellefȳr, equivalent to hell + fire. Cognate with West Frisian helfjoer (“hellfire”), Dutch hellevuur (“hellfire”), German Höllenfeuer (“hellfire”).