'inveterate' originates from Latin, specifically the word 'inveteratus,' where 'in-' meant 'in' and 'vetus' meant 'old.'

'inveteratus' transformed into the French word 'invétéré,' and eventually became the modern English word 'inveterate' through Middle English.

Initially, it meant 'long-standing or old,' but over time it evolved into its current meaning of 'habitual or chronic.'