'recap' originates from the English word 'recapitulate', which comes from the Latin word 'recapitulare', where 're-' meant 'again' and 'capitulum' meant 'chapter'.

'recapitulate' transformed into the shortened form 'recap' in modern English usage.

Initially, it meant 'to go over the chapters again', but over time it evolved into its current meaning of 'to summarize'.