The Spanish word 'concha' meaning 'shell' has ancient roots tracing back to Ancient Greek 'κόγχη' (konkhe), which meant 'shell' or 'mussel'. This Greek word was borrowed into Latin as 'concha', keeping the same meaning. Latin also had a diminutive form 'conchula' meaning 'small shell', and it's from this Latin form that the Spanish word 'concha' ultimately developed.

The word 'concha' is fairly basic in Spanish and is commonly used, so there aren't many simpler related words. However, you might encounter derivatives like 'conchero' (a place where shells accumulate) or 'conchudo' (shelled).

English speakers might recognize this etymology in words like 'conch', which refers to a specific type of marine shell or the sea creature that lives in it. The word 'conchology', meaning the study of shells and mollusks, also comes from the same Greek root. These cognates maintain a clear connection to the original meaning of shells or shell-like objects.