'elongated-snouted' is a compound formed from the adjective 'elongated' and the adjective 'snouted'. 'elongated' derives from Latin 'elongatus', the past participle of 'elongare' (from 'e-'/ex- 'out' + 'longus' 'long'); 'snout' comes from Middle English 'snout(e)', related to Old English/Old Norse words for 'nose' or 'snout'.

'elongate' entered English via Latin 'elongare'/'elongatus' (through Medieval/Modern Latin and French influence) and developed into the English adjective 'elongated'; 'snout' existed in Middle English as 'snout(e)' and evolved into the modern English 'snout', and the two were joined as a descriptive compound in modern English to form 'elongated-snouted'.

Individually, 'elongated' originally meant 'made long' and 'snout' meant 'nose' or 'muzzle'; combined, the compound came to mean specifically 'having an unusually long snout', a straightforward compositional meaning with little semantic shift.