'amenorrheic' originates from Greek, specifically the word 'amenorrhoia,' where 'a-' meant 'without,' 'men' referred to 'month,' and 'rhoia' meant 'flow.'

'amenorrhoia' transformed into the modern English word 'amenorrhea,' and the adjective form became 'amenorrheic.'

Initially, it meant 'without monthly flow,' and this meaning has largely remained the same in modern usage.