The Spanish word 'energía' comes from Latin 'energia', which was borrowed from Ancient Greek 'energeia' meaning 'force' or 'capacity for action'. The Greek word was formed by combining three elements: the prefix 'en-' meaning 'in', the root 'ergon' meaning 'work' or 'action', and the suffix '-eia' which was used to form abstract nouns. So literally, the word was built to mean something like 'the state of being in action' or 'having the capacity for work'.

This construction reflects how we think about energy today - as the capacity to do work or cause change, whether it's electrical energy powering our devices or the chemical energy we get from food.

Some related Spanish words include 'enérgico' (energetic), which describes someone full of energy, and 'energético' (energetic, relating to energy). These words share the same Greek root and maintain the core meaning of force or capacity for action.

The English word 'energy' is a direct cognate of Spanish 'energía', sharing the same Greek origin. Other related English words include 'ergonomics' (the study of work efficiency), which contains the same Greek root 'ergon' meaning 'work', and 'synergy' (combined effort), which uses the same root with a different prefix 'syn-' meaning 'together'.