The Spanish word 'cien' (meaning 'hundred') comes from the Latin word 'centum', which also meant 'hundred'. The word evolved through Old Spanish 'ciento', and was shortened to 'cien' in modern Spanish. Note that 'cien' is used before nouns (like 'cien años' - hundred years), while the form 'ciento' is still used in certain contexts, particularly in compounds like 'doscientos' (two hundred).

Several common Spanish words are related to 'cien' through the Latin root 'centum'. For example: 'centavo' (cent, one-hundredth), 'centenar' (a hundred of something), 'centena' (group of hundred), and 'porcentaje' (percentage). All these words maintain a connection to the concept of 'hundred' or division by hundred.

Many English words share the same Latin ancestor 'centum'. Common examples include 'cent' (one-hundredth of a dollar), 'century' (period of 100 years), 'percent' (per hundred), and 'centennial' (happening every 100 years). The 'cent-' prefix in English consistently relates to the concept of 'hundred', making it easy to recognize the connection between these English words and the Spanish 'cien'.