'Angus' originates from Scottish Gaelic, specifically the word 'Aonghas' (also 'Aonghus'), where 'óen-' meant 'one' and 'gus' meant 'strength; vigor'.

'Angus' changed from Old Irish word 'Óengus' (later Gaelic 'Aonghas/Aonghus'), became the Scottish place-name 'Angus', and eventually became the modern English word 'Angus' (also naming the cattle breed).

Initially, it referred to a personal name and a Scottish region, but over time it also came to denote the well-known beef cattle breed 'Angus'.