'disfrutar' originates from Vulgar/ Late Latin, specifically from a formation like 'disfructare' (from Latin 'fructus'), where the prefix 'dis-' conveyed separation or intensification and 'fruct-' (from Latin 'fructus') meant 'fruit' or 'enjoyment'.

'disfructare' (Vulgar Latin) developed into Old Spanish forms such as 'desfrutar' / 'disfrutar' and eventually stabilized as modern Spanish 'disfrutar'.

Initially it carried the sense 'to enjoy the fruit/benefit of something' (a somewhat concrete sense tied to 'fruits' or benefits); over time it broadened to the general sense 'to enjoy' or 'to take pleasure in'.