'betray' originates from Old French, specifically the word 'trahir,' where 'tra-' meant 'across' and '-hir' meant 'to hand over.'

'trahir' transformed into the Middle English word 'betrayen,' and eventually became the modern English word 'betray.'

Initially, it meant 'to hand over treacherously,' but over time it evolved into its current meaning of 'to be disloyal or reveal secrets.'