'hygrometer' originates from Greek, specifically the word 'hygros,' meaning 'wet' or 'moist,' and 'metron,' meaning 'measure.'

'hygros' and 'metron' combined in Greek to form 'hygrometron,' which evolved into the modern English word 'hygrometer.'

Initially, it meant 'an instrument for measuring moisture,' and this meaning has largely remained the same in modern usage.