The word 'spud' has obscure origins, first appearing in Middle English to denote a short, sharp tool. Its application to a digging tool in the 17th century established its connection with soil and roots. This association with root vegetables, particularly the potato, became firmly established in the 19th century, transforming 'spud' into a common, informal synonym. The word's journey from a tool to a tuber exemplifies semantic shift based on functional association.

This word is a simplex. Its origin is uncertain but may be related to Middle English 'spudde', meaning a short knife or dagger, or possibly of Scandinavian origin.