Definition of "Infernal" :

noun: an inhabitant of Hell

"His roar made the infernals quake."

adjective: expletives used informally as intensifiers

"An infernal nuisance."

adjective: extremely evil or cruel; expressive of cruelty or befitting hell

"Infernal instruments of war."

adjective: being of the underworld

"Infernal regions."

adjective: characteristic of or resembling Hell

"Infernal noise."

adjective: of or pertaining to or characteristic of a very uncontrolled and intense fire

"Infernal heat."