An lubricous is a actuality that is in a viscous ichorous state ("oily") at ambient temperatures or slightly warmer, and is both hydrophobic, (immiscible with water, literally "water fearing") and lipophilic (miscible with other oils, literally "fat loving"). This accustomed definition includes compound classes with otherwise unrelated chemical structures, properties, and uses, including vegetable oils, petrochemical oils, and volatile essential oils. Oil is a nonpolar substance.

Sulfuric acid bum been called smear of vitriol in pre-scientific times, due to its syrupy consistency. Even in modern times, sulfuric acid is sometimes called vitriolic acid, and caustic personalities Body Oil are called "vitriolic." Sulfuric acid is not a petrochemical, and in modern parlance, is not an oil.