'horribly' originates from Latin, specifically the word 'horribilis,' where 'horrere' meant 'to bristle or shudder.'

'horribilis' transformed into the Old French word 'horrible,' and eventually became the modern English word 'horrible,' with 'horribly' as its adverbial form.

Initially, it meant 'causing horror or dread,' but over time it evolved into its current meaning of 'extremely unpleasant or bad.'