'round-snouted' originates from Modern English compounding of the adjective 'round' (from Old French 'rond', ultimately from Latin 'rotundus', where 'rotundus' meant 'round') and the noun 'snout' (from Middle English 'snout', likely from Old Norse 'snūtr', where 'snūtr' meant 'nose').

'round' entered English via Old French 'rond' from Latin 'rotundus'; 'snout' appears in Middle English as 'snout' (possibly from Old Norse 'snūtr'); in Modern English the two words were joined as the compound adjective 'round-snouted'.

Initially the parts meant 'round' and 'nose' respectively; combined in Modern English they straightforwardly mean 'having a round snout', a descriptive sense that has remained stable.