The Spanish word 'esencia' (meaning 'essence') comes from the Latin word 'essentia', which also meant 'essence'. The Latin term was influenced by two sources: the Greek word 'ousia' (meaning 'essence' or 'being') and the Latin verb 'esse' (meaning 'to be'). The Greek 'ousia' itself derived from the Greek verb 'eimi' meaning 'to be'. This shows how the concept of 'essence' is deeply connected to the fundamental idea of 'being' or 'existing' in both ancient Greek and Latin thought.

A related Spanish word is 'ser' (to be), which though it looks different, shares the same conceptual root as it comes from Latin 'esse'. Another related word is 'esencial' (essential), which is more directly visible in its connection to 'esencia'.

English speakers can easily connect 'esencia' to several familiar words: 'essence', 'essential', and 'quintessential'. All these words share the same Latin root 'essentia'. The connection is clear both in spelling and meaning - they all relate to the core or fundamental nature of something.