'serendipitous' originates from 'serendipity', which was coined by Horace Walpole in 1754, inspired by the Persian fairy tale 'The Three Princes of Serendip', where the princes were always making discoveries by accidents and sagacity.

'Serendipity' was coined in the 18th century and evolved into 'serendipitous' in the 20th century, eventually leading to the adverb 'serendipitously'.

Initially, it meant 'making discoveries by accident', but over time it evolved into its current meaning of 'happening by chance in a happy or beneficial way'.