'antiphthisic' originates from Greek via New Latin, specifically the word 'antiphthisikos', where 'anti-' meant 'against' and 'phthisis' meant 'consumption (tuberculosis)'.

'antiphthisic' changed from Greek 'antiphthisikos' into New Latin/Late Latin 'antiphthisicus' and eventually became the modern English word 'antiphthisic'.

Initially, it meant 'against phthisis (consumption)'; over time this meaning has largely remained, retaining the sense 'preventing or counteracting consumption'.