The Spanish word "mundo" (meaning "world") comes from the Latin word "mundus", which meant both "world" and "universe". Interestingly, the Latin "mundus" was actually influenced by the Ancient Greek word "κόσμος" (kosmos), which originally meant "order" and later came to mean "universe" - reflecting the ancient Greek philosophical view of the universe as an ordered system.

Some common Spanish words derived from the same root include "mundial" (worldwide), which you might recognize from "Copa Mundial" (World Cup). Another related word is "inmundo" (filthy, unclean), which literally means "unworldly" or "not clean" - playing on the sense of "mundus" that also meant "clean" or "elegant" in Latin.

English speakers might recognize this root in words like "mundane" (ordinary, worldly rather than spiritual), "municipal" (relating to a city or its government), and "cosmopolitan" (the latter coming from the Greek "kosmos"). The word "mundane" especially shows how the meaning evolved from "of the world" to "ordinary" - since worldly things were considered less special than heavenly ones in medieval thinking.