'afterswell' originates from the combination of 'after' and 'swell', where 'after' indicates a subsequent event and 'swell' refers to a wave or series of waves.

'afterswell' is a compound word formed in English, combining 'after' and 'swell' to describe a specific maritime phenomenon.

Initially, it meant 'a subsequent wave', and this meaning has largely remained the same in modern usage.