Jäännösoli
Jäännösoli is a Finnish term that translates to "residual oil" or "leftover oil." It generally refers to oil that remains in a container after the primary contents have been used or poured out. This can apply to various types of oils, including cooking oils, motor oils, and industrial lubricants. The amount of jäännösoli can vary greatly depending on the viscosity of the oil, the shape of the container, and how thoroughly it has been emptied.
In the context of cooking, jäännösoli might be the film of oil left in a frying pan