What is described as the force between two bodies that are in contact by moving in opposite directions?

The term that describes the force between two bodies that are in contact and moving in opposite directions is friction. Friction is the force that resists the relative motion or tendency of such motion of two surfaces in contact. It plays a crucial role in various applications, such as the way vehicles grip the road or how one object can slide against another.

When two surfaces are moving against each other, the type of friction at play is usually dynamic friction, which is specifically the resistance encountered by an object in motion sliding across a surface. However, in this context, the broader term "friction" encompasses both static and dynamic forms, thus correctly attributing the described force to it.

By referring to friction in general, the definition accounts for interactions under motion (as seen in dynamic friction) and ensures a comprehensive understanding of the forces at play in contact situations.