'vex' originates from Latin, specifically the word 'vexare,' where 'vex-' meant 'to shake or disturb.'

'vexare' transformed into the Old French word 'vexer,' and eventually became the modern English word 'vex' through Middle English.

Initially, it meant 'to shake or disturb,' but over time it evolved into its current meaning of 'to irritate or annoy.'