The Spanish verb 'cargar' (meaning 'to load') comes from the Vulgar Latin word 'carricare', which also meant 'to load'. This Vulgar Latin term was derived from the Classical Latin word 'carrus', which meant 'wheeled vehicle'. The semantic evolution makes intuitive sense - the action of loading something often involved putting goods onto wheeled vehicles for transport in ancient times.

Several common Spanish words share this same Latin root, including: 'carro' (car), 'carreta' (cart), 'carroza' (carriage), and 'cargo' (cargo, load). All these words maintain a connection to the original concept of vehicles and transportation of goods.

English speakers might recognize this etymology in words like 'cargo', 'car', 'carry', and 'charge' - all of which can be traced back to the same Latin root 'carrus'. The connection is especially clear in 'cargo' (goods being transported) and 'carry' (to transport or bear a load), which share the basic meaning of transportation or bearing weight with Spanish 'cargar'.