General terms:
* Crude: This is often used to refer to unrefined oil, especially petroleum.
* Black gold: This poetic term is used for petroleum, highlighting its economic value.
* The black stuff: A more casual term for petroleum.
* Slick: Often used in reference to oil spills or its slippery nature.
* Grease: A general term for oily substances.
Specific terms:
* Motor oil: For oil used in car engines.
* Cooking oil: For oil used in cooking.
* Baby oil: For oil used for moisturizing babies.
* Essential oil: For oils extracted from plants.
Slang terms:
* The juice: A slang term for oil, particularly in the context of oil drilling and the energy industry.
* The black goo: A more informal term for petroleum.
The best informal term to use depends on the situation and the specific type of oil you are referring to.
