Why is oil called a hydrophobic substance?

In chemistry, hydrophobicity refers to the physical property of a molecule that is repelled from a mass of water.
Hydrophobic molecules tend to be a non-polar and thus prefers neutral molecules and non-polar solvents. Hydrophobic molecules in water often cluster together forming micelles. Water on hydrophobic surfaces will exhibit a high contact angle.
Examples of hydrophobic molecules include alkanes, oils, fats, and greasy substances in general. Hydrophobic materials are used for oil removal from water, the management of oil spills and chemical separation processes to remove non-polar from polar compounds.