The Spanish word 'polvo' meaning 'dust' comes from the Vulgar Latin form '*pulvus', which developed from Classical Latin 'pulvis', also meaning 'dust'. The evolution from Latin to Spanish shows typical sound changes, where the 'u' became 'o' and the final '-is' was simplified to '-o', giving us the modern Spanish form 'polvo'.

Some related Spanish words include 'polvoso' (dusty), 'polvoriento' (dusty), and 'polvorear' (to dust or sprinkle with powder). The word 'pólvora' (gunpowder) is also derived from the same Latin root, as gunpowder was originally conceived as a type of dust or powder.

While English 'dust' is not related to 'polvo', there are some English words that share the Latin ancestor 'pulvis'. These include 'pulverize' (to reduce to powder or dust), 'pulverous' (consisting of powder or dust), and 'pulverulent' (covered with dust or powder). These words entered English through Latin and French, maintaining their connection to the concept of dust or powder.