'alarm' originates from Old French, specifically the word 'alarme', where 'a-' meant 'to' and 'larme' meant 'arms'.

'alarme' transformed into the English word 'alarm', and eventually became the modern English word 'alarumed' as a past tense form.

Initially, it meant 'to call to arms', but over time it evolved into its current meaning of 'to cause fear or anxiety'.