Related to hell or extremely annoying and unpleasant; can also mean deserving of hell or absolutely awful.
From Latin 'infernalis,' from 'infernus' (lower, hellish), related to 'inferno.' The word originally referred to the underworld in mythology and religion.
Medieval people used 'infernal' seriously to describe hell itself, but modern speakers use it casually for anything annoying—'that infernal noise!'—it's a perfect example of how religious language becomes everyday vocabulary when we need dramatic words for life's frustrations.
Complete word intelligence in one call. Free tier — 50 lookups/day.