means A slippery, water-resistant liquid—whether pressed from plants, rendered from animals, or pumped from underground—used for fuel, lubrication, cooking, or painting.

from English borrowed it through Old French 'oile' from Latin 'oleum,' meaning olive oil specifically—itself a cousin of the Greek 'elaion,' from 'elaia,' the olive. For the ancient Mediterranean world, oil simply meant the pressed juice of the olive; only later did the word stretch to cover every greasy liquid we squeeze, render, or drill from the earth. The 'oil' and the 'olive' are, etymologically, the same word wearing different clothes.