hellfire I. \ˈ ̷ ̷| ̷ ̷\noun Etymology: Middle English, from hell + fire 1.: the fire of hell : fire and brimstone < an old-fashioned Calvinist sermon on hellfire > 2.: something that torments like the fire of hell (as burning spite or resentment) II. adjective : fire-and-brimstone < a hellfire preacher > < preached on a hellfire topic >