'clap' originates from Old English, specifically the word 'clæppan' (or 'clappen'), probably of imitative origin meaning 'to strike' or 'to make a sharp sound'.

'clap' changed from Old English 'clæppan' through Middle English forms such as 'clappen' and eventually became the modern English word 'clap'.

Initially it meant 'to strike' or 'to make a sudden sharp sound'; over time it also developed the sense 'to applaud' and other figurative uses.