The Spanish word 'túnel' comes from English 'tunnel', which itself can be traced back to Old French. The Old French word 'tonnelle' meant 'small barrel' or 'funnel-shaped net' and was formed by combining 'tonna' (meaning 'skin' or 'vessel') with the diminutive suffix '-elle'. The word evolved from referring to something barrel or funnel-shaped to specifically meaning an underground passage, likely due to the tunnel's tube-like shape resembling a barrel or funnel.

While 'túnel' was borrowed directly from English rather than inherited from Latin or Old French, there aren't many common Spanish words that share its exact etymology. However, Spanish students might find it helpful that 'túnel' is one of the easier Spanish words to remember since it's so similar to its English counterpart, just with an added accent mark on the 'u'.

The English word 'tunnel' is obviously related to Spanish 'túnel', since Spanish borrowed it directly from English. English speakers might also be familiar with the word 'ton', which comes from the same Old French root 'tonna' that meant a large vessel or cask. The word 'tun', meaning a large cask or barrel, is another related term, though it's less commonly used in modern English.