noun (Automotive engineering: Fuels, oils, emissions, and other fluids) Mineral oil is a light hydrocarbon which is a product of petroleum and is used as a lubricant. ⇒ To ensure that the rollers glide easily, industrial grade mineral oil is used. ⇒ Brake fluid is highly corrosive and lacks the lubricating properties of a mineral oil. ⇒ Vegetable oils were once preferred to mineral oils, particularly for sports and competition cars.
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