The Spanish word 'tarjeta' (meaning 'card') has an interesting evolution that starts with the Frankish word 'targa', meaning 'shield'. This word made its way into Old French as 'targe', keeping the same meaning. In Old French, the diminutive suffix '-ette' was added to 'targe' to create 'targette', meaning 'small shield'. This Old French word was then borrowed into Spanish, evolving into 'tarjeta'.

The semantic shift from 'small shield' to 'card' makes sense when you consider that both objects are flat, relatively small items that can hold or display information - shields often displayed heraldic designs or family crests, while cards display text, numbers, or other information.

While 'tarjeta' itself is a commonly used Spanish word for 'card', there aren't many simpler or more common Spanish words that share its etymology. This is because it came into Spanish as a direct borrowing from Old French.

English speakers might be interested to know that the English word 'target' is actually related to 'tarjeta', as both come from the same Frankish root 'targa' meaning 'shield'. While 'tarjeta' evolved to mean 'card' in Spanish, the English word 'target' retained more of its original meaning related to something you aim at (like a shield), though it has expanded to include any goal or objective. The English word 'targe' (a type of medieval shield) is also directly related, though it's rather rare and archaic today.