'bladder' originates from Old English, specifically the word 'blǣdre,' where 'blǣd' meant 'blow' or 'blast,' referring to the bladder's ability to expand.

'blǣdre' transformed into the Middle English word 'bladdre,' and eventually became the modern English word 'bladder.'

Initially, it meant 'a sac or pouch,' but over time it evolved into its current meaning of 'a muscular sac in the pelvis that stores urine.'