'repressor' originates from Latin, specifically the word 'reprimere,' where 're-' meant 'back' and 'premere' meant 'to press.'

'reprimere' transformed into the French word 'réprimer,' and eventually became the modern English word 'repress' through Middle English.

Initially, it meant 'to press back or restrain,' and over time it evolved into its current meaning of 'a protein that inhibits gene transcription.'