The Spanish word 'rehén' (meaning 'hostage') traces its origins to Arabic, reflecting the historical influence of Arabic-speaking Muslims in medieval Spain. It comes from the Andalusi Arabic 'rihán' (meaning 'hostages'), which was the plural form. This word developed from Classical Arabic 'rihan' (plural) and ultimately from 'rahn', meaning 'pledge' or 'hostage'. The evolution from Arabic to Spanish involved the adaptation of Arabic sounds to Spanish phonology, with the Arabic 'i' becoming 'e' and the final 'n' being retained but with Spanish stress patterns.

While 'rehén' is a relatively unique word in Spanish derived from Arabic, there aren't many commonly used, simpler Spanish words that share its etymology. This reflects its specific borrowing from Arabic during the period of Muslim rule in Spain.

There aren't any common English words directly related to 'rehén' since it comes from Arabic rather than the shared Latin or Germanic roots that typically connect English and Spanish words. English words for similar concepts like 'hostage' and 'pledge' come from different etymological sources.