'narrow-beaked' originates from Modern English, formed by combining the adjective 'narrow' and the noun 'beak' with the adjectival/participial suffix '-ed' to mean 'having a narrow beak'.

'narrow' comes from Old English 'nearu' meaning 'narrow, close'; 'beak' comes via Middle English 'bek' from Old French 'bec' (ultimately a Germanic root). The compound itself is a straightforward Modern English formation combining those elements.

The component words originally meant 'narrow' and 'beak' separately; the compound has retained the literal sense and has been used in biological and descriptive contexts to denote birds or animals with a narrow beak.