'relaxant' originates from Latin, specifically the word 'relaxare,' where 're-' meant 'again' and 'laxare' meant 'to loosen.'

'relaxare' transformed into the French word 'relaxant,' and eventually became the modern English word 'relaxant' through Middle English.

Initially, it meant 'to loosen or make less tight,' but over time it evolved into its current meaning of 'a substance that relaxes muscles.'