'habit-forming' originates from the combination of 'habit' and 'forming', where 'habit' meant 'a settled or regular tendency or practice' and 'forming' meant 'shaping or creating'.

'habit-forming' changed from the concept of 'habit' in Middle English, which was 'habite', and eventually became the modern English word 'habit-forming'.

Initially, it meant 'creating a regular practice', but over time it evolved into its current meaning of 'causing addiction or dependency'.