Infernal means belonging to hell, or thoroughly annoying. Infernal regions, this infernal noise, an infernal machine.
The mild sense is the everyday one and is a softened oath: calling a noise infernal is a way of swearing without swearing. The literal sense belongs to Dante and to theology. An infernal machine was a nineteenth-century name for a bomb.
1adjectiveinfernalBelonging to hell, or thoroughly annoying.
“I couldn't sleep because of that infernal car alarm going off all night.”
infernal is a quality.
INFERnal → not INTERNAL, it comes from below
It is not internal at all: the heat and the noise come up from somewhere far below the building, and they never stop.
hooks ontointernal
Latin infernalis comes from infernus, the world below, from inferus, lower.
Latin
infernus
Medieval Latin
infernalis
Middle French
infernal
Old French
infernal
English, today
infernal
Built from
Borrowed from Middle French -, from Old French infernal. From Middle French infernal, from Medieval Latin infernalis, from Latin infernus, from inferus (“netherworld, underworld, hell”), equivalent to inferno + al.
Etymology from Wiktionary, CC BY-SA