'laxative' originates from Latin, specifically the word 'laxare', where 'lax-' meant 'loose' and the suffix '-ative' indicated an adjective or agent.

'laxare' passed into Medieval Latin as 'laxativus' (meaning causing loosening), and this developed into the English word 'laxative' in the early modern period.

Initially it meant 'causing loosening' in a general physical sense; over time it came to refer specifically to substances or medicines that loosen the bowels.