The Spanish preposition 'entre' meaning 'between' comes from the Latin word 'inter', which also meant 'between' or 'among'. The Latin 'inter' itself was formed by combining two elements: the prefix 'in-' meaning 'in, within' and the contrastive suffix '-ter'. This combination created a word that expressed the concept of being in the space that separates or connects two or more things.

Several common Spanish words are built using 'entre-' as a prefix, such as 'entrar' (to enter), 'entrada' (entrance), and 'entremedio' (in between). These words all share the core idea of being within or between something.

Many English words share this Latin root 'inter-', making them cousins of the Spanish 'entre'. Common examples include 'international' (between nations), 'interrupt' (to break between), 'interval' (space between), and 'intermediate' (in the middle between). The English prefix 'inter-' and Spanish 'entre-' both preserve the original Latin meaning of 'between' or 'among'.