The Spanish word 'aceite' (meaning 'oil') traces its origins through Arabic influence in medieval Spain. It comes from the Andalusi Arabic 'azzáyt' meaning 'olive oil', which in turn descended from Classical Arabic 'azzayt' with the same meaning. The ultimate source is the Aramaic word 'zayta', also meaning 'olive oil'. This etymology reflects the historical importance of olive oil in Mediterranean cultures and the significant influence of Arabic on Spanish vocabulary during the centuries of Muslim rule in the Iberian Peninsula. The word underwent phonetic changes as it moved from Aramaic through Arabic and finally into Spanish, with the Arabic 'z' sound becoming a 'c' in Spanish, and the final 't' softening to 'te'.

The Spanish word 'aceituna' (meaning 'olive') is closely related to 'aceite', as both come from the same Arabic root. This connection makes intuitive sense since olives are the source of olive oil. Another related Spanish word is 'aceitero/a', which can refer to an oil vendor or an oil container.

Unlike many Spanish words that have cognates in English, 'aceite' doesn't have any closely related English words because it came into Spanish through the Arabic influence rather than through the shared Latin heritage of English and Spanish. English words for oil-related concepts typically come from Latin 'oleum' (giving us 'oil') or Greek 'elaion' (as in 'oleander').