'after-lunch' originates from English, as a compound of 'after' (from Old English 'æfter', where 'æfter' meant 'after/behind') and 'lunch' (a shortening of 'luncheon' in modern English, meaning 'a light meal').

'lunch' changed from the earlier English word 'luncheon' (18th–19th century), shortened in modern usage to 'lunch'; 'after-lunch' was formed in modern English by compounding 'after' + 'lunch' to describe time or position relative to the meal.

Initially it referred specifically to events 'following a light meal' (luncheon); over time it has retained that temporal sense and is used generally to mean 'occurring after lunch'.