'sepal' originates from New Latin, specifically the word 'sepalum', where the Greek root 'skepē' meant 'covering'.

'sepal' changed from the New Latin word 'sepalum' (coined in modern botanical Latin) and entered English botanical usage in the 19th century as 'sepal'.

Initially, it meant 'a covering' (from the Greek root), but over time it evolved into the current specific botanical sense of 'one of the outer parts of a flower that protects the developing bud'.