'long-nosed' originates from English, specifically a compound of 'long' and 'nosed' (from 'nose' + the adjectival suffix '-ed'). 'long' originates from Old English 'lang', where Proto-Germanic '*langaz' meant 'long'; 'nose' originates from Old English 'nosu', where Proto-Germanic '*nusô' meant 'nose'.

'long' developed from Old English 'lang' into Middle English 'long', and 'nose' developed from Old English 'nosu' into Middle English 'nose'; the adjectival compound combining 'long' + past-participial/adjectival 'nosed' formed in Modern English and became the current compound 'long-nosed'.

Initially, it meant 'having a long nose' and this basic descriptive sense has largely remained the same into modern usage.