'prejudicial' originates from Medieval Latin, specifically the word 'praeiudicialis,' where 'prae-' meant 'before' and 'iudicium' meant 'judgment.'

'praeiudicialis' transformed into the Old French word 'prejudiciel,' and eventually became the modern English word 'prejudicial' through Middle English.

Initially, it meant 'pertaining to a judgment made in advance,' but over time it evolved into its current meaning of 'harmful or biased.'