'slender-snouted' originates from modern English compounding of 'slender' (from Middle English 'slendre') and 'snout' (from Middle English 'snout'), where 'slender' meant 'thin' and 'snout' meant 'nose or projecting mouth'.

'slender' developed from Middle English 'slendre' (with possible Old Norse influence) and retained the sense of 'thin'; 'snout' was used in Middle English (possibly influenced by Old Norse 'snutr') to mean a projecting nose. The compound form 'slender-snouted' arose in modern English by joining these elements to describe animals with a thin snout.

Initially the component words meant 'thin' and 'nose' respectively; over time the compound came to be used specifically to describe animals possessing a thin, projecting snout.