'angelus' originates from Latin, specifically the word 'angelus', where 'angelus' meant 'angel'.

'angelus' was adopted directly from Medieval Latin 'angelus', referring to the prayer beginning with the words 'Angelus Domini nuntiavit Mariae' ('The Angel of the Lord declared unto Mary'), and eventually became the modern English word 'angelus'.

Initially, it meant 'angel', but over time it evolved to refer specifically to the prayer and the bell rung to announce it.