'groan' originates from Old English, specifically the word 'grānian,' where 'grān-' meant 'to lament or mourn.'

'grānian' transformed into the Middle English word 'gronen,' and eventually became the modern English word 'groan.'

Initially, it meant 'to lament or mourn,' but over time it evolved into its current meaning of 'to make a low sound in pain or despair.'