'flask' originates from Middle English 'flaske', from Old French 'flasque' (meaning a bottle or container), ultimately influenced by Medieval Latin 'flascum' (a flask or bottle), though the ultimate origin is uncertain and may be Germanic.

'flask' changed from Middle English 'flaske' (and Old French 'flasque') and eventually became the modern English word 'flask'.

Initially, it meant 'a bottle or container for liquids' and over time it specialized to include scientific glassware (laboratory flasks) and small portable containers for spirits (hip flasks).