'arbitrary' originates from Latin, specifically the word 'arbitrarius,' where 'arbitr-' meant 'judge or witness.'

'arbitrarius' transformed into the Old French word 'arbitraire,' and eventually became the modern English word 'arbitrary' through Middle English.

Initially, it meant 'dependent on the will or judgment of an arbiter,' but over time it evolved into its current meaning of 'random or capricious.'