The Spanish word 'corcho' (meaning 'cork') traces back to the Latin word 'cortex', which meant 'bark' or 'rind'. This word evolved through Mozarabic (the Romance language spoken by Christians living under Muslim rule in medieval Spain) as '*korčo', before finally becoming the modern Spanish 'corcho'. This etymology makes intuitive sense since cork is literally tree bark, specifically from the cork oak tree (Quercus suber).

A related Spanish word is 'corteza', which means 'bark' or 'crust'. Both 'corcho' and 'corteza' share the Latin root 'cortex', with 'corteza' maintaining the original meaning of tree bark in general, while 'corcho' specialized to refer specifically to cork material.

The English word 'cortex' is directly borrowed from the same Latin word 'cortex'. While in Spanish 'corcho' evolved to specifically mean 'cork', in English 'cortex' retained more technical meanings, referring to the outer layer of an organ (like the cerebral cortex in the brain) or the outer tissue of stems and roots in plants. The English word maintains the original Latin sense of 'outer layer' or 'bark'.