'halibut' originates from Middle English, specifically the word 'halybutte', where 'haly' meant 'holy' and 'butte' meant 'flatfish'.

'halybutte' transformed into the modern English word 'halibut'.

Initially, it meant 'holy flatfish', as it was often eaten on holy days, but over time it evolved into its current meaning of a type of large flatfish.