'two-nostriled' originates from Modern English, formed from the numeral 'two' and the noun 'nostril', where 'two' ultimately comes from Old English 'twā' meaning '2' and 'nostril' derives from Old English 'nosthyrl' meaning 'nose-hole'.

'nostril' changed from the Old English word 'nosthyrl' (literally 'nose-hole') through Middle English forms into the modern English 'nostril', and the compound adjective 'two-nostriled' is a later Modern English formation combining 'two' + 'nostril' + adjectival '-ed'.

Initially, the element corresponding to 'nostril' meant 'nose-hole', and over time it has come to denote the nostril; the compound's meaning—'having two nostrils'—is a straightforward descriptive development.