'nostril' originates from Old English, specifically the word 'nosthyrl', where 'nosu' meant 'nose' and 'thyrl' (related to 'thirl') meant 'hole' or 'opening'.

'nosthyrl' (Old English) changed into Middle English forms such as 'nostril' and eventually became the modern English word 'nostril' (plural 'nostrils').

Initially, it meant 'nose-hole' or 'opening of the nose', and over time it has retained this core meaning as the term for the external openings or passages of the nose.