'composure' originates from Middle English, specifically the word 'composure', where 'com-' (from Latin) meant 'together' and 'ponere' meant 'to put/place'.

'composure' changed from Old French forms (such as 'composure' or related derivatives) and from Late Latin 'compositura' (from 'componere'), eventually becoming the modern English word 'composure'.

Initially, it meant 'the action or result of putting together or arranging' (related to 'compose'), but over time it evolved into the current meaning of 'calmness or self-control'.